B2B marketing agencies: what to hire one for, and how to judge the work

Hire a B2B marketing agency to create and progress pipeline against a defined list of target accounts, not to produce traffic or leads in the abstract. Scope the first engagement as a paid discovery project rather than a retainer, agree the lead definitions and the sales follow up rules before any campaign starts, and judge the first ninety days on the diagnosis and the output while you wait for pipeline. The commercial answer arrives in two stages: pipeline created in the first quarter, revenue influenced in the second or third.

B2B buying is slow, committee driven and mostly invisible to your analytics. That changes what an agency can be held to, how the contract should read, and which numbers mean anything before the cycle completes.

What is actually different about B2B

The differences are practical. Each one changes a decision you will make in the engagement, starting with the fact that a small target market is optimised for fit rather than volume.

Dimension	B2C	B2B, and the consequence
Who decides	One person, often quickly	A buying committee: a user, an economic owner, often procurement, security or legal. You need material for each role, not one persuasive page.
Cycle length	Minutes to days	Weeks to quarters. Work started in March can show up as revenue in September, so monthly revenue reporting is noise.
What convinces	Offer and price	Evidence: a named reference in the same sector, a security document, a workable implementation plan.
Attribution	Mostly trackable	Much of the research happens where there is no click: a peer group, a comparison page, an assistant, a conversation. Self reported source carries real information.
Channel economics	Cheap clicks, thin margins	Expensive clicks, high deal values. A click price that looks absurd can still be your best buy.

What a B2B agency can be held to

Most disappointing engagements come from a mismatch here. Write the split down in the first week.

• Theirs: output shipped on date to an agreed bar, reach into the account list, cost per qualified conversation, correct tracking and honest reporting.
• Shared: message and positioning, lead definitions, which accounts are in scope, review turnaround.
• Yours alone: pricing, sales follow up speed, the product, and deciding what counts as a win.

The four kinds of firm sold as a B2B agency

• Demand generation. Paid media, landing pages, lifecycle email, the pipeline number. Right when you have a product people already search for and you need volume.
• Account based marketing. A named list, coordinated contact across channels, close work with sales. Right for high value deals and a short target list. It depends on sales participation, so only buy it if your sales team will join the weekly call.
• Brand, creative and positioning. How you explain what you do and why it matters. The work with the widest effect and the hardest to measure, best bought as a fixed project.
• Channel specialists. Search, content, paid search, LinkedIn, events, public relations. Buy one when you already know which channel to improve. Two specialists plus an internal owner often beats one full service retainer, because you pay senior rates only where you need senior thinking.

Ask any firm which of the four it is. One that claims all four is usually reselling its junior team.

How to structure the engagement

Buy a discovery project first. Four to six weeks, fixed price, with written deliverables: interviews across your last ten won and lost deals, the target account list with its selection logic, the positioning statement, a channel plan with a budget split, and the measurement plan. You get something useful even if you never sign the retainer, and you learn how they work before committing a year.

Settle the definitions before the first campaign. Three short documents prevent most later arguments.

• The ideal customer profile, written as filters a person can apply: sector, employee band, geography, technology in use, trigger event. Vague profiles produce leads nobody wants.
• The lead stages, with the exact criteria for each handover and who owns the record. Decide what a marketing qualified lead means here, then stop renegotiating it mid quarter.
• The follow up rule, stating how fast sales contacts an enquiry and how many attempts are made before it returns to nurture. Agencies get blamed for lead quality when the real problem is a three day response time.

Keep the assets and the access. Ad accounts, analytics, the content management system and the domain stay in your name with the agency added as a user. Write into the contract what you keep on exit: content files, research, ad creative, documentation and the reporting template.

Run one weekly meeting with a standing agenda: what shipped, what is blocked waiting on you, what the numbers did, what changes next week. Underperforming retainers are more often starved of client decisions than effort.

Reading the numbers while the cycle is still running

You do not have to wait two quarters to know whether this is going well. Read leading indicators early and lagging ones late.

When	What a healthy engagement looks like
Weeks 1 to 4	A written diagnosis naming the three things holding growth back, with evidence from your own data. Tracking fixed, first assets shipped, account list agreed.
Months 2 to 3	Reach into target accounts rising. Qualified conversations booked. Cost per qualified conversation stable enough to forecast with. Sales says the enquiries are recognisably the right companies.
Months 4 to 6	Pipeline created that traces back to the work, including by self reported source. Win rate on agency sourced deals comparable to the rest. Sales using the content inside live deals, which is a strong quality signal.
Months 7 to 12	Revenue influenced, payback period on acquisition cost, and a repeatable channel mix you could brief a new team on tomorrow.

Two habits are worth the small effort. Put one open field on every form asking how the person heard about you, because in B2B that answer often names a channel analytics never sees. And report pipeline by the month the contact first appeared, not the month the deal closed.

Red flags

• A proposal that arrived before anybody asked about your deal sizes, sales cycle or win rate.
• Reporting built on impressions, rankings or raw lead counts with no mention of fit.
• A fixed number of blog posts or leads per month as the main deliverable. Buying leads by the unit often buys the same list your competitors bought.
• A twelve month lock in with no notice period and nothing delivered in month one.
• Work done inside the agency's own accounts, where you cannot see it or take it with you.
• A pitch that will not name the firm's own failures. Google's own guidance is blunt that no one can guarantee a number one ranking, and it is worth reading before you take any growth claim at face value: Do you need an SEO.

This page covers selecting, scoping and managing a B2B marketing agency. For the questions to put to a search specialist and how retainer pricing is structured, see how to choose an SEO agency. For rates, send one identical scope to three firms of different sizes.

Asked and answered: B2B marketing agencies

Should we hire an agency or build the team in house?

Use an agency when you need several skills at once and cannot yet justify a salary for each, or when you want an outside diagnosis. Hire in house once the work is steady and tightly coupled to the product. Most companies end up with an in house owner holding the strategy and specialists bought around them.

How long before an agency engagement pays for itself?

Model it from your own sales cycle: median time from first contact to closed deal, plus a month for the work to ship, is the earliest point revenue can appear. Set the first commercial review there.

What is a reasonable budget split across channels?

Fund the channel your last ten won deals came from, then test one new channel at a time on a defined budget with a decision date attached. Testing three at once on a small budget each produces three inconclusive results.

Is a sector specialist better than a generalist?

A specialist earns the premium when your market has its own language or compliance rules, such as healthcare, finance or defence. Ask which of your competitors they work with and how they handle the conflict. For technical and creative craft, pick on the quality of the people.

How do we measure something as slow as brand?

Three practical measures: search volume for your company name, the share of enquiries that name you first rather than a category, and win rate in deals where you were invited rather than prospecting. Review them quarterly.

One question to add to every agency pitch

Ask each firm what a buyer sees when they put your category question to ChatGPT, Gemini, Perplexity, Claude or Google's AI Overviews. In B2B this is now part of the research path, particularly for committee members who never speak to sales.

Those five answer differently, name different companies and cite different sources, and they run no shared ranking, so a strong position in one tells you nothing about the others. Most agencies are not asked this yet, which makes it a quick way to find out who is paying attention. Run the check yourself first, using your buyers' real wording and keeping your own company name out of the prompt so the answer is clean. AI Knows Us is one way to run it on a schedule.