Key Findings
The 8 agencies on this list have collectively served 25,000+ B2B clients and employ thousands of SDRs across multiple continents. They are mature operators, not hypotheticals. The question is not whether they work, it's which one fits your stage and budget.
Belkins has the best review consistency and dedicated SDR model at mid-market scale. CIENCE has the largest team and the proprietary graph8 data platform. Callbox has 20+ years of operation and the strongest multi-region infrastructure, particularly in APAC.
Leadium and Cleverly start under $1,500/month for SMBs. Martal, SalesHive, and entry-tier Belkins sit $4,000 to $8,000/month. CIENCE mid-tier runs $8,000 to $15,000/month. Callbox Pods start at $15,000/month per region. Match the pricing tier to your deal size and revenue, not to brand recognition.
If you sell complex technical products to CTOs or engineering buyers, vertical specialization beats generalist capacity. Operatix works exclusively with B2B software. Martal has 16+ years of tech vertical focus. Generalist agencies can ramp on your ICP, but specialists ramp faster.
Traditional lead gen agencies rent you pipeline through SDR teams. Claygencies build you infrastructure through Clay-based workflows. Pick the model that matches your stage, budget, and whether you want dedicated headcount or transferable systems. The right agency follows the right model.
Most buyers shopping for a B2B lead generation agency in 2026 end up on the same shortlist. Belkins. CIENCE. Martal. Callbox. A few others depending on who they asked. These agencies have been around for a decade or more, they have named case studies, thousands of reviews, and the operational infrastructure to run SDR teams at scale. For a lot of companies, one of them is the right answer.
But not for all of them. A new category called Claygencies has taken over the top of the market for mid-market B2B companies that want signal-based multichannel outbound instead of volume SDR teams. The two models are not the same, and pretending they compete head-to-head is how buyers end up with the wrong fit.
This article ranks the 8 traditional B2B lead generation agencies most mid-market and enterprise buyers evaluate in 2026, based on track record, specialization, pricing, and review consistency. We rank them fairly on their own terms, not against the Claygency playbook. Then at the end, we cover when a traditional agency is the right call and when a Claygency actually fits better. Reachly is a Claygency, so we have skin in this question. We think honest framing beats forcing a ranking where Reachly sits at #1 against agencies that play a different game.
What Is a B2B Lead Generation Agency?
A B2B lead generation agency is a service provider that helps other businesses find, qualify, and engage potential buyers, usually through outbound channels like cold email, LinkedIn outreach, and cold calling. Instead of the client hiring and training an internal SDR team, the agency runs top-of-funnel prospecting and delivers qualified meetings or sales-ready leads directly to the client's calendar.
Most B2B lead generation agencies fall into one of three categories. Appointment setting agencies focus on booking meetings directly, often using large offshore SDR teams running phone-heavy outreach. Cold email specialists build email infrastructure and run sequences at volume, sometimes layering LinkedIn on top. Multichannel full-service agencies coordinate email, phone, LinkedIn, and sometimes paid touches into a single campaign, manage replies, and take the engagement through to the booked meeting.
Pricing spans a wide range. Budget appointment setting runs $1,000 to $3,000/month, typically on bought lists. Mid-market agencies sit at $3,500 to $10,000/month for multichannel work. Enterprise agencies with large SDR pods and fractional executive services charge $15,000 to $30,000/month or more. Most require a 3 to 6 month minimum commitment because outbound compounds. First meetings usually land in month 1, break-even around month 3, and healthy campaigns show 3 to 5x ROI by month 6.
The category has split in 2026. Traditional lead generation agencies still dominate on scale, brand recognition, and SDR headcount. A newer category called Claygencies has taken over the top of the mid-market by rebuilding the playbook around Clay, Smartlead, and HeyReach with signal-based targeting at the core. Both models work for the right buyer. The rest of this article covers how to tell which is which.
How We Ranked the Top B2B Lead Generation Agencies
Agency ranking articles usually skip the methodology. We're not going to, because without criteria the list is just opinion.
Here are the seven factors we weighted. These are tuned for evaluating traditional lead generation agencies specifically, not Claygencies. The Claygency ranking uses different criteria because the two models solve different problems.
The 8 Top B2B Lead Generation Agencies in 2026 (At a Glance)
Before the detailed writeups, here is the full ranked list.
- Belkins
- CIENCE Technologies
- Martal Group
- Callbox
- Operatix
- SalesHive
- Leadium
- Cleverly
The 8 Top B2B Lead Generation Agencies in 2026
1. Belkins
Belkins is a Delaware-headquartered B2B lead generation and appointment setting agency, founded in 2017 by Michael Maximoff and Vladislav Podolyako. They have grown to a global team of 200+ employees serving over 1,000 clients across 50+ industries, including General Electric, Nvidia, Zendesk, and Cloudflare.
The approach is omnichannel appointment setting with an emphasis on manual, human-verified research and proprietary email deliverability tooling via their Folderly platform. Belkins assigns a dedicated account manager and SDR team to each client, running coordinated campaigns across email, LinkedIn, cold calling, and sometimes WhatsApp. Typical engagements produce 100 to 400 qualified appointments per year. They report a 10:1 average ROI and a 25% average closing rate across verticals.
Pricing sits in the $5,000 to $25,000+/month range depending on scope and number of channels. Clutch reviews show strong consistency with 230+ reviews averaging 4.8 stars, and G2 backs that up. Industries served include SaaS, IT services, financial services, healthcare, manufacturing, and professional services.
Best for: Mid-market and enterprise B2B companies that want a dedicated SDR team, omnichannel execution, and strong email deliverability infrastructure backed by a large, operationally mature agency.
Where Belkins wins: Scale plus deliverability. The Folderly infrastructure and 200+ person team mean campaigns land in the inbox and run consistently over 12+ months, which matters for long sales cycles.
2. CIENCE Technologies
CIENCE is a Denver-based B2B lead generation and go-to-market services company, founded in 2015. They have 1,200+ employees across four continents and have served more than 2,500 clients across 225+ industries. Clients include Okta, Yamaha, and hundreds of other technology and services brands.
What sets CIENCE apart is the software layer. Their graph8 AI platform (formerly CIENCE GO) includes a 140M+ contact database, intent data, multichannel campaign orchestration, and visitor identification. Most traditional lead gen agencies resell third-party tools. CIENCE built theirs, which means the SDR team and the data layer run on the same stack. The company operates on two tracks: managed SDR services and platform access.
Pricing runs $3,000 to $15,000+/month depending on team size and service scope. Contracts are typically month-to-month since their recent pivot, which is an advantage over competitors requiring 3 to 6 month minimums. Honest flag: G2 and Clutch reviews are mixed. Some clients report excellent results and pipeline growth, others cite SDR turnover, inconsistent lead quality, or months without meaningful meetings booked. The size of the operation means experience varies by account.
Best for: Enterprise and mid-market B2B companies that want a proprietary data platform plus SDR services under one roof, and can tolerate variable account-level experience in exchange for scale.
Where CIENCE wins: The graph8 platform. If you value owning access to a 140M+ contact database alongside a managed SDR team, very few other agencies offer that combination.
3. Martal Group
Martal Group is a Canada-based B2B lead generation and sales outsourcing agency, founded in 2009 in Oakville, Ontario. They run onshore SDR teams across North America, the EU, and LATAM, focused almost exclusively on B2B SaaS, IT services, cybersecurity, and tech verticals. Over 16 years in operation, they have served 2,000+ B2B brands.
The model combines experienced human SDRs with their proprietary AI SDR platform, which handles prospecting across a large B2B database enriched with intent and technographic signals, AI-enhanced copywriting, omnichannel sequencing, and email deliverability management. Martal offers three pricing tiers: standard lead generation, deal closure plus customer onboarding, and full account management. Most campaigns begin producing qualified leads within 30 days.
Pricing starts around $3,600/month with most clients in the $4,000 to $8,000/month range. Minimum engagement is typically a 3 to 4 month pilot. G2 reviews are generally strong, with clients praising the industry pattern recognition for B2B tech specifically. Martal is one of the few agencies that can take engagements beyond appointment setting into deal closure and account management, which makes them a hybrid sales outsourcing partner rather than a pure lead gen shop.
Best for: B2B tech and SaaS companies (especially Series A to C) that want onshore SDRs with vertical specialization, and flexibility to extend the engagement into deal closure or account management.
Where Martal wins: Tech vertical depth. If you sell complex technical products to CTOs and engineering leaders, Martal's SDRs know the terminology and buyer psychology better than a generalist agency.
4. Callbox
Callbox is the longest-operating agency on this list, founded in 2004 and headquartered in Encino, California. Over 20+ years they have delivered 1.3 million qualified leads across 20,000+ lead generation programs for 15,000+ clients in 60+ countries. They have delivery hubs in the Philippines and satellite offices in Singapore, Australia, and Malaysia.
The model is the Campaign Pod: a specialized team of researchers, SDRs, and account managers assigned to each client, executing across six channels (phone, email, LinkedIn, chat, webinars, and programmatic ads). Their Pipeline CRM and Smart Engage platform orchestrate the outreach, and they have deep vertical specialization in technology, SaaS, cloud, cybersecurity, fintech, manufacturing, and logistics. Four of the five largest companies in the world use Callbox for some combination of outsourced sales and marketing.
Pricing runs $15,000 to $30,000 per Campaign Pod covering one region or language. Multi-region campaigns require multiple Pods, so international programs typically land between $45,000 and $90,000. They don't charge hourly or pay-per-appointment. The model assumes clients want full-service multi-region execution, not a test budget.
Best for: Enterprise B2B companies running global campaigns across multiple regions and languages, particularly in APAC where Callbox has the strongest on-the-ground footprint of any traditional agency.
Where Callbox wins: Global reach and APAC depth. No other traditional agency has the same multi-region infrastructure for tech companies selling into Singapore, Australia, Malaysia, and the Philippines simultaneously.
5. Operatix
Operatix is a UK-based sales acceleration agency, founded in 2012 in Fleet, England, now part of memoryBlue after a 2023 acquisition. They work exclusively with B2B software and SaaS vendors, running dedicated SDR teams that operate as extensions of clients' sales and marketing functions. 300+ staff across offices in the UK, Dallas, San Jose, and Singapore, with programs running in 20+ languages.
The focus is account-based outbound into named enterprise accounts, with a specialty in helping software vendors expand into new geographic markets. Services include outbound SDR programs, inbound lead qualification, channel partner recruitment, and ABM acceleration. Since the memoryBlue acquisition, they operate within a broader SMART services framework (Sales, Marketing, Academy, Recruiting, Technology), giving them deeper North American coverage alongside the EMEA and APAC strength they built independently.
Pricing is custom. Programs are structured around dedicated SDR teams and named accounts, which puts them in the higher-touch, higher-cost end of the market. Minimum engagements typically assume enterprise-level budgets.
Best for: B2B software and SaaS vendors expanding into new regions (EMEA, LATAM, APAC) who need multilingual SDRs with sector-specific training.
Where Operatix wins: Software-only specialization plus multilingual regional expansion. If you need SDRs who speak German, French, or Japanese for technical enterprise software sales, few agencies go deeper than Operatix.
6. SalesHive
SalesHive is a Denver-based outsourced SDR company, founded in 2016 by Brendan Burnett. 250+ employees split between US-based and Philippines-based SDR teams, with 117,000+ meetings booked for 1,500+ clients since launch.
The differentiator is operational flexibility. SalesHive offers month-to-month contracts with 30-day cancellation, which is rare in an industry that typically locks clients into 3 to 6 month minimums. Their proprietary eMod AI engine personalizes email outreach at scale (claimed ~68% open rates), and their Power Dialer enables 150 to 500+ touches per day per SDR for high-volume cold calling programs. Every plan includes a US-based strategist regardless of whether the SDRs are US or Philippines-based.
Pricing is published transparently on their site: US SDR plans run $7,000 to $12,000/month, Philippines-based plans start at $4,500/month. Annual commitments save around 10%. Independent reviews on Trustpilot are mixed, with some consistent criticism the agency hasn't responded to publicly. Show rate on booked meetings is claimed at 85%+, though that figure is vendor-reported rather than independently audited.
Best for: Mid-market B2B companies that need cold calling capacity fast, want month-to-month contract flexibility, and prioritize phone-based outreach as a core channel.
Where SalesHive wins: Contract flexibility plus phone volume. Month-to-month contracts let you test outbound without long-term commitment, and the Power Dialer infrastructure handles cold calling at a volume most agencies can't match.
7. Leadium
Leadium is a US-based B2B lead generation and appointment setting agency. Smaller and more boutique than the agencies above, they run full-service sales outsourcing with a focus on manual research, rigorous ICP definition, and channel-optimized outbound across email, phone, LinkedIn, SMS, and strategic gifting.
The workflow is collaborative: client approves the target list before campaigns launch, and research quality is a stated priority over automated list-building. They have built a strong reputation on boutique-grade lead research and appointment setting for companies that value curation over volume.
Pricing starts at $1,000+/month minimum, with flexible retainers depending on scope. That lower entry point makes them accessible to SMBs and growing mid-market teams who don't yet have the budget for Belkins or CIENCE but want a real agency relationship rather than a freelancer. Reviews on Clutch average 4.9 stars with frequent praise for pricing, though some mention onboarding delays.
Best for: SMB and growing mid-market B2B companies that want high-touch, boutique-style appointment setting with manual research and a collaborative account relationship.
Where Leadium wins: Accessible pricing with a strategic approach. They give smaller B2B teams access to real lead gen methodology without enterprise-level commitment.
8. Cleverly
Cleverly is a US-based LinkedIn-first lead generation agency, expanded into cold email and cold calling. CEO Nick Verity has built the agency into one of the most reviewed LinkedIn-focused shops, with 10,000+ clients generating 224,700+ B2B leads that resulted in $312M in pipeline revenue and $51.2M in closed revenue. Client logos include Amazon, Google, Uber, PayPal, Slack, and Spotify.
The LinkedIn plan is their anchor: $397/month for managed LinkedIn outreach using your profile for connection requests and multi-touch messaging sequences. They offer a pay-per-lead model on cold email (you pay only for meeting-ready leads) and a cold calling service with guaranteed appointments. That pricing structure is unusual in the industry and makes them accessible for companies testing outbound without large retainers.
Honest flag: the lower price point and templated approach come with trade-offs. Reviews are split. Some clients report consistent qualified lead flow. Others report lead quality issues, delayed dashboards, reused lead lists, or locked 3-month contracts not clearly disclosed upfront. LinkedIn Sales Navigator ($100+/month) is required but not included in the advertised price. Real monthly cost including Sales Navigator is closer to $500 to $800.
Best for: Companies that want LinkedIn as a primary channel, teams testing cold outreach on a smaller budget, or B2B companies with decision-makers who live on LinkedIn.
Where Cleverly wins: LinkedIn specialization plus accessible pricing. If LinkedIn is your buyer's primary channel and you want done-for-you outreach under $500/month, there are few alternatives at that price point.
How to Choose the Right Lead Gen Agency for Your Stage
Agency selection breaks down along three honest axes.
Stage. Early-stage companies without product-market fit should not hire a lead generation agency of any kind. Outbound amplifies whatever you already have. If your offer doesn't convert warm referrals, outbound won't fix it. Wait until you have repeatable closed-won deals from at least two acquisition channels before paying for outbound execution.
Budget. Match the pricing tier to your deal size. If your average deal is $10,000 and an agency books 5 qualified meetings per month that close at 20%, that's one deal per month covering a $5,000/month agency fee with 2x ROI. Under $5,000 average deals, the math gets harder. Under $30,000 monthly revenue, most of these agencies are the wrong call.
Outcome ownership. This is the question most buyers don't ask until it's too late. At the end of your engagement, what do you keep? Most traditional agencies run everything inside their own infrastructure (domains, sending accounts, CRM data, campaign workflows). When you leave, the infrastructure leaves with them. You're renting pipeline, not building it. Some agencies are clearer about this upfront than others. Ask the question before signing.
When a Claygency Might Be the Better Fit
Here's the honest framing. A traditional lead generation agency and a Claygency are not competing for the same problem. Picking between them starts with knowing what you actually need.
Pick a traditional agency when: you need a large SDR team making phone calls at volume, you run multi-region campaigns in 5+ languages (Callbox territory), you have complex enterprise deals that require human nurturing over 6+ month cycles, you want the brand reassurance of hiring an agency with 1,000+ published clients, or you have the budget for $10,000 to $30,000+/month engagements and want dedicated SDR headcount.
Pick a Claygency when: you want signal-based targeting (hiring moves, funding rounds, tech stack changes) instead of list-based outreach, you want multichannel orchestration built into one system rather than three departments, you prefer to own the infrastructure (domains, mailboxes, Clay workspace, workflows) when the engagement ends, you want to launch in 2-3 weeks instead of 4-8, you're a mid-market B2B company with a budget of $3,500 to $10,000/month, or you want to test signal-based outbound before committing to a large SDR operation.
Reachly is a Claygency. Triple-certified across Clay, Smartlead, and HeyReach, running done-for-you signal-based multichannel outbound for B2B companies globally. If the Claygency framing fits your situation better than traditional lead gen, our detailed Claygency ranking covers the full category.
The traditional lead gen model was designed for a market where you could buy a list, send 10,000 emails, and book meetings from volume alone. That market is gone. Deliverability tightened, buyer fatigue set in, and the 1% reply rate that used to justify the economics no longer covers agency fees. The agencies on this list adapted by adding SDR headcount, deliverability tooling, and multichannel orchestration. The good ones still deliver. But if you're asking whether to hire one, the first question is not "which agency is best," it's "which model fits my stage and budget." Pick the model first, then pick the agency.
Red Flags When Hiring Any Lead Gen Agency
Regardless of which category the agency sits in, a few warning signs apply.
🚩 They cannot produce named case studies. "We have helped hundreds of clients" with no named logos and no specific pipeline or meeting numbers usually means the results do not exist at the claimed scale. Every agency on the ranked list above publishes named clients with verifiable figures. If yours won't, push for specifics before signing.
🚩 They report on opens and clicks. Open rates have been broken by Apple Mail Privacy Protection since 2021. Clicks are unreliable because link-tracking is disabled by many enterprise clients. Any agency in 2026 still leading with open and click rates as performance metrics is reporting activity, not outcomes. Ask for meeting-booked rates, pipeline generated, and reply-to-meeting conversion.
🚩 They charge a large diagnostic fee before execution. Healthy agencies can tell you within two calls what the engagement looks like, what it will cost, and how month 1 will play out. Diagnostic phases that bill $20,000+ before anyone touches a sequence are usually scope-creep, not strategic rigor.
🚩 Pricing is vague even after multiple calls. Transparent agencies give you a range based on scope within the first call. Vague pricing through three discovery calls is usually a signal they're anchoring high before quoting.
🚩 They refuse to discuss what you keep on day 91. As discussed above, this is the sharpest question. If the agency gets defensive or deflects, you already have your answer.
Frequently Asked Questions
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