A lead generation agency finds potential buyers for your business, starts conversations with them, and hands you the ones who are interested, either as warm replies or as booked meetings. What that looks like day to day depends on the type of agency: some send cold email, some work LinkedIn, some make calls, some run ads and content, and some simply sell you data. This guide breaks down the five main types of B2B lead generation agency, what each one delivers, and how to choose the one that matches how you sell.
What a lead generation agency does, in one paragraph
Every lead generation agency, whatever the channel, does four jobs: it defines who you should be selling to, finds those people, gets their attention with a relevant message, and qualifies the response before passing it to you. The differences between agencies come down to which channel they use, how much of that work they do, and where they hand off to your sales team.
That handoff point matters more than most buyers realize. "Lead" can mean anything from a downloaded PDF to a booked call with a decision-maker. Before comparing agencies, agree on what you are buying.
| Term | What it usually means | Who does the next step |
|---|---|---|
| Contact or record | Name, title, company and email or phone | You do all the outreach |
| MQL (marketing qualified lead) | Someone who engaged with content or an ad | Your team qualifies and reaches out |
| Positive reply | A prospect who replied with interest to outreach | Your team replies and books |
| SQL (sales qualified lead) | A prospect qualified against your criteria | Your team runs discovery |
| Booked appointment | A meeting on your calendar | Your team shows up and sells |
The 5 main types of lead generation agency
1. Outbound email agencies
What they do: Build separate sending domains and inboxes, warm them up, build a targeted prospect list, write sequences and send personalized emails at scale. Interested replies go to you or to the agency's team, depending on the model.
What you get: Positive replies from prospects who match your ideal customer profile. Some agencies also book the meeting.
Typical engagement: A setup period of a few weeks (warmup is the main reason), then monthly campaigns. Pricing is usually a monthly retainer. Published anchors include SoPro at around $3.8K a month and Pearl Lemon Leads from £2,497 a month.
Best for: B2B companies that can name their target companies and titles, and have a market of at least a few thousand potential buyers.
Watch out for: Agencies that send from your main domain, skip warmup, or report opens instead of replies. Our cold email agency guide walks through a typical week-by-week launch.
2. LinkedIn lead generation agencies
What they do: Optimize your profile, send connection requests and follow-up messages, and sometimes run content or ghostwriting alongside outreach. Some combine LinkedIn with email.
What you get: Conversations with prospects in LinkedIn messages, and booked calls if the agency handles scheduling.
Typical engagement: Monthly retainer, usually tied to one or a few LinkedIn profiles. LinkedIn limits how many connection invitations an account can send each week, so volume per profile is capped regardless of what the agency promises.
Best for: Markets where buyers are active on LinkedIn (founders, agency owners, marketing and sales leaders, recruiters), and offers where the sender's personal credibility matters.
Watch out for: Agencies that need your login and run aggressive automation, which can put your account at risk. See our overview of LinkedIn lead generation services for how a managed approach works.
3. Calling and SDR agencies
What they do: Provide outsourced sales development reps who call, email and message prospects, qualify them and book meetings. This is the closest thing to renting an SDR team.
What you get: Booked appointments with prospects who have passed some qualification criteria.
Typical engagement: Monthly retainer per rep or per program, sometimes with a fee per meeting. It is often more expensive than email-only work because people are doing the outreach. Belkins, for example, shows a "from $5,000" a month card on its cold email page that includes a guaranteed appointment figure. For comparison with hiring, Payscale lists an average US SDR base salary of about $51,677 in 2026, before tools, data, commission and management time.
Best for: Higher-value deals, complex offers that need a live conversation to qualify, and teams that want meetings rather than replies.
Watch out for: Meetings that don't show or don't qualify. Agree on what counts as a qualified meeting before you start. Our appointment setting agency page explains how a meeting-focused program is set up.
4. Paid and inbound lead generation agencies
What they do: Run paid ads (search, LinkedIn Ads, Meta), landing pages, gated content, webinars and SEO to attract prospects who raise their hand.
What you get: Form fills, demo requests and content downloads (MQLs), which your team then qualifies.
Typical engagement: A management fee plus your ad spend, often with a minimum term because campaigns need time to optimize. SEO and content programs take longer still.
Best for: Markets where buyers actively search for a solution, companies with budget for ads, and products with a clear category name people already type into Google.
Watch out for: Reporting that stops at cost per lead. A cheap form fill that never becomes a sales conversation is not a cheap lead.
5. Data vendors and list providers
What they do: Sell or license B2B contact and company data, sometimes with enrichment and intent signals. Some services build a custom list for you once; others give you software access.
What you get: Records: names, titles, emails, phone numbers and company details. No outreach.
Typical engagement: Software subscription or a one-off list fee. As of October 2026, Apollo's Basic plan is listed by third-party sources at $49 per user per month on annual billing. Enterprise data providers often quote custom prices instead of publishing them.
Best for: Teams that already have the people and process to run outreach and just need better data.
Watch out for: Old or recycled lists, unverified emails (which raise bounce rates and hurt deliverability), and data you can't legally use in your target countries.
Side-by-side comparison
| Agency type | Main channel | What you receive | Typical pricing model | Time to first result | Your team's job |
|---|---|---|---|---|---|
| Outbound email | Cold email | Positive replies, sometimes meetings | Monthly retainer, sometimes pay per lead | About 3 to 6 weeks (warmup first) | Reply, book, close |
| LinkedIn messages | Conversations, sometimes meetings | Monthly retainer per profile | A few weeks | Take calls, close | |
| Calling and SDR | Phone plus email | Booked, qualified meetings | Retainer per rep, sometimes per meeting | Several weeks, depending on ramp | Run meetings, close |
| Paid and inbound | Ads, SEO, content | Form fills and demo requests | Management fee plus ad spend | Weeks for ads, months for SEO | Qualify, follow up, close |
| Data vendor | None | Contact records | Subscription or list fee | Immediate | All outreach and selling |
Pricing models deserve their own comparison, because "pay per lead" and "retainer" carry very different risks. See pay per lead vs retainer for how each one works and the contract terms to ask for.
Want a second opinion? If you're not sure which type of agency fits your market, book a 30-minute call with David at Koldify. Koldify is an email agency, but David will tell you if another channel is a better fit.
What a typical engagement looks like
Whatever the type, a well-run lead generation engagement tends to follow the same arc.
- Discovery. The agency learns your offer, your best customers, your sales process and what a qualified lead means to you.
- Targeting. Together you define the ideal customer profile: industries, company size, geography, job titles and buying triggers. You share exclusion lists (customers, open deals, competitors).
- Setup. Infrastructure, accounts, tracking, landing pages or lists, depending on the channel. For cold email this includes domain setup and inbox warmup, which is why email programs have a built-in lag before the first send.
- Messaging approval. You review and approve the copy, scripts or ads before anything goes live.
- Launch and learn. The first month is mostly testing: which segment responds, which angle works, which objections come up.
- Optimize and scale. Weak segments are cut, strong ones get more volume, and reporting shifts toward meetings and pipeline.
- Handoff and feedback. Your team reports back on lead quality so the agency can tighten targeting.
That last step is where many engagements fail. If your sales team never tells the agency which leads were good, the agency is optimizing blind.
How to pick the type that fits
Answer these five questions honestly and the right type usually becomes obvious.
How many potential buyers exist?
- Thousands or more: outbound email can reach them efficiently.
- Hundreds: each prospect deserves more research and a more personal touch. LinkedIn, calling, or very targeted email work better.
- You don't know: start with a data tool and count them before hiring anyone.
Are your buyers searching for what you sell?
- Yes, and there is a known category: paid search and SEO can capture that demand.
- No, they don't know they need it yet: outbound (email, LinkedIn, calls) creates the conversation.
How much is a new customer worth?
- High value: you can afford human-heavy outreach, such as an SDR agency or a meeting-based program.
- Moderate value: email-first outreach usually has the best cost per conversation.
- Low value: agencies rarely pay back; focus on inbound, partnerships or self-serve.
Who will handle the response?
- You have someone ready to reply and sell: an agency that hands you positive replies is enough.
- You have no one to follow up: you need an appointment setting or SDR agency, or you need to fix capacity first.
How fast do you need an answer?
- Within two months: outbound email or calling will tell you fastest whether your offer works.
- Over two quarters: inbound and SEO compound over time.
When you have a shortlist of agencies of the right type, use our lead generation agency checklist to score them against the same criteria.
Where Koldify fits
Koldify is a done-for-you cold email agency run by David Tile (Nerdy Joe is its content site). In the categories above, it is an outbound email agency.
- It owns and operates its own sending infrastructure, with no middlemen, and sends from separate domains, never your main domain.
- Inboxes get about three weeks of warmup; campaigns typically launch around week four.
- Lists, offer and copy are built with you and approved before launch.
- Replies are routed to you, and your team handles the conversation, booking and closing.
- Month-to-month, no long-term contract.
Koldify publishes these figures on koldify.io: 10M+ cold emails sent, 50K+ leads generated, $10M+ in pipeline and $2M+ in revenue generated for clients. One client, Black Stone Funding Group, got 120+ leads in 60 days; another, Skrapper, got 140+ interested leads.
It is not the right fit if you want an agency to run calls and book meetings for you, if you sell to consumers, or if your total market is a few hundred accounts that need hand-crafted outreach. You can see the full scope on the lead generation services page, or book an intro call with David to talk through your market.
If you'd rather run it yourself: the DIY stack
If you have someone with time to learn, outbound email is the easiest channel to run in-house. Some tool links here are affiliate links (disclosure).
| Job | Tool | Price as of October 2026 | Notes |
|---|---|---|---|
| Find and verify contacts | Apollo | Free plan; Basic $49 per user per month on annual billing (third-party sources) | Large B2B database with built-in verification |
| Send and warm up | PlusVibe | Personal $37 a month (25,000 emails); Business $77 a month (150,000 emails) | Generous email and active-lead limits for the price |
| Send and warm up (alternative) | Smartlead | Base $39 a month (6,000 sends); Pro $94 a month (90,000 sends) | API and client workspaces from Pro |
| Domains and inboxes | Bought through your sending tool or a provider | Smartlead lists Google inboxes at $4.50 a month and domains at $13 a year | Never use your main domain for cold email |
The software is the easy part. The hard parts are the ones an agency is paid for: choosing the right segment, writing an offer strangers care about, and keeping inboxes healthy enough to land. Give yourself at least a month of warmup and testing before deciding whether the channel works.
Signs DIY is working (and signs it isn't)
Run the stack for a couple of months, then check honestly:
- Working: bounces stay low, inboxes stay out of spam, and you get a steady trickle of replies from the right titles.
- Working: at least some replies turn into calls your team would have wanted anyway.
- Not working: replies are mostly unsubscribes or "wrong person," which usually points to a targeting problem rather than a copy problem.
- Not working: your sending tool shows falling placement or rising bounces, which means the infrastructure needs attention before you send more.
- Not working: nobody on your team has time to keep the campaigns fed with new lists and fresh angles.
If you land in the second group, that's the point where an agency or a hire usually pays for itself. If you want to compare options at that stage, book a call with David at Koldify and bring your numbers.
Sources
- Payscale, Average Sales Development Representative (SDR) Salary (updated May 29, 2026): https://www.payscale.com/research/US/Job=Sales_Development_Representative_(SDR)/Salary
- Belkins, Cold email services (pricing card): https://belkins.io/cold-email-services
- SoPro, Pricing: https://sopro.io/pricing/
- Pearl Lemon Leads, Cold email: https://pearllemonleads.com/cold-email/
- LinkedIn Help, Invitation limit reached: https://www.linkedin.com/help/linkedin/answer/a550555
- Koldify, results and client case studies: https://koldify.io
- Apollo pricing, as reported by Saleshandy (Sept 2026) and Valley (Oct 2026): https://www.saleshandy.com/blog/apolloio-pricing/ and https://www.joinvalley.co/blog/apollo-pricing-and-credits-explained-2026
- PlusVibe, Pricing: https://plusvibe.ai/pricing
- Smartlead, Pricing: https://www.smartlead.ai/pricing
Frequently asked questions
What is a B2B lead generation agency?
A B2B lead generation agency finds and engages potential business buyers on your behalf, then hands you the ones who show interest. Depending on the agency, that might be through cold email, LinkedIn, phone calls, paid ads and content, or by selling you contact data.
Do lead generation agencies close deals?
Most do not. A lead generation agency fills the top of your funnel with interested prospects or booked meetings, and your team runs the sales conversation and closes. A few full-cycle sales outsourcing firms will also close, but that is a different service.
What is the difference between a lead and an appointment?
A lead is usually a prospect who has shown interest, such as a positive reply to an email. An appointment is a meeting that is already booked on your calendar. Agencies that sell appointments typically charge more per unit because they do more of the work.
Is it better to hire a lead generation agency or build an in-house team?
An agency is usually faster to start and cheaper to test, because you skip hiring, ramp time and tool setup. An in-house team gives you more control and can make sense once you have proven which channel and message work.
Which type of lead generation agency is best for a small B2B company?
For most small B2B companies with a clear target list, an outbound email agency is the lowest-cost way to test demand. If your buyers are very active on LinkedIn or your market is small and high value, a LinkedIn or calling-focused agency may fit better.
What should a lead generation agency report on?
At minimum: activity (emails sent, connection requests, calls), positive replies or conversations, meetings booked and, ideally, pipeline created. Be cautious of reports that lead with opens, impressions or clicks.