How to Choose a Paid Social Agency (UK Buyer’s Checklist)

Every paid social agency pitch looks the same. A slide on audience precision, a slide on creative that "cuts through", a funnel diagram, a logo wall. The differences that determine whether you get pipeline or an invoice for impressions only surface around month three — which is precisely when the contract you signed makes it awkward to leave.

This is a checklist for finding those differences before you sign. It is written for B2B buyers in the UK, it assumes you care about revenue rather than reach, and it is upfront about the fact that we are a paid social agency ourselves. Weigh our advice accordingly — and note that every test below is one we are happy to sit.

The Three Paid Social Agency Archetypes

Almost every agency on your shortlist is one of three animals. Two of them fail in predictable ways, and the failure is baked into how they are built, not how hard they try.

Archetype one: the media buyer with stock creative

These agencies are genuinely good at the machinery — campaign structure, conversion tracking, bid strategy, the endless housekeeping of Business Manager. Creative, though, is treated as an input: something you supply, or something assembled from templates and stock footage by a designer three time zones from your strategy.

The failure mode is structural. Platform automation has quietly absorbed most of the targeting and bidding work these agencies used to sell. What the algorithms cannot do is make a film your buyers stop scrolling for, which means creative is now the biggest lever on the account — and it is the one lever this archetype does not hold.

You will feel it around month three. Performance plateaus, and the monthly report grows a polite line about "creative fatigue" alongside a request for fresh assets. The problem you hired an agency to solve is now your job again.

Archetype two: the creative shop that hands off files

The mirror image. These teams make genuinely lovely work — properly shot, properly graded, the sort of film a brand team enjoys approving. Then they export the deliverables, hand over a folder, and wish you luck with distribution.

The failure mode here is the severed feedback loop. The editors never see that viewers drop off at second four, so nobody re-cuts the hook. The ad that underperforms simply stays underperforming, beautifully. And because the shop is paid per project rather than on performance, the incentive to fix any of this rounds to zero.

Archetype three: the integrated create-and-distribute partner

The third model makes the ads and runs the media under one roof and one accountability. When the retention graph shows the hook failing, the edit changes that week. When a LinkedIn ad works, a YouTube cut of it exists days later. Media data stops being a report and becomes a production brief.

Full disclosure: this is the model we run as a paid social agency, so we are hardly neutral. You do not have to take our word for the logic, though — the checklist below works on any agency, us included.

The person making your next ad should know what your last ad did. Every question on this checklist is, one way or another, a test of that loop.

The 10-Point Buyer's Checklist

Run every shortlisted agency through all ten. The answers matter less than how quickly and specifically they arrive — a good agency has fielded these questions a hundred times and rather enjoys them.

1. Is creative production in-house? Ask who will physically make your ads — names, not departments. If the answer involves "our creative partners" or a freelancer marketplace, you are buying a media buyer with a subcontracting habit. An agency with real corporate video production capability can turn a losing ad into a winning one in days rather than procurement cycles.
2. What is the platform mix, and can they justify it? For B2B, expect a considered answer: LinkedIn for targeting precision, Meta for cost-efficient reach into the same buyers off the clock, YouTube for watch time and retargeting pools. Distrust the single-platform specialist for whom everything is a Meta problem, and equally the shop claiming deep expertise on six platforms with a team of four.
3. Do they report on pipeline, not clicks? Ask to see a real, anonymised client report. If the front page is impressions, CPM and CTR, that is what they optimise — you manage what you present. The front page should show qualified leads, pipeline influenced and cost per opportunity, with platform metrics relegated to the appendix where they belong.
4. Are the fees transparent? UK retainers typically run somewhere between £2,000 and £10,000+ a month, or 10–20% of ad spend, depending on scope — the number matters less than knowing exactly what it buys. Ask whether creative is included or billed separately, whether tools carry a markup, and whether the percentage-of-spend model gives them an incentive to recommend more spend. It does. Ask how they manage it.
5. How long is the contract? Three months rolling is fair: it covers the genuine setup investment without holding you hostage. A twelve-month lock-in with a ninety-day notice period is a confidence signal, and not in the direction the agency intends.
6. Who owns the ad accounts? You do. Non-negotiable. Campaigns run in your Business Manager and your LinkedIn account, with the agency granted partner access you can revoke. More on this below, because it is the single most expensive mistake on this list.
7. What is the creative testing cadence? Ask how many new variants enter the account each month and what triggers a refresh. B2B audiences are small, so creative fatigues in weeks, not quarters. An agency that ships a batch at launch and "optimises" it for six months is running a media plan from 2016; a proper video advertising agency treats the account as a rolling production schedule.
8. Can they show B2B references? B2C brilliance does not transfer. Long sales cycles, five-figure deal sizes, buying committees and tiny addressable audiences change everything about how paid social is planned and judged. Ask for case studies with pipeline numbers attached, then ask to speak to one of the clients behind them.
9. Who actually runs your account? Agencies are routinely pitched by the founder and serviced by whoever joined last month. Meet the day-to-day team before you sign, and ask how many accounts each person manages. Beyond eight or so, yours is a dashboard glance on a Friday afternoon.
10. What are the offboarding terms? When you leave — and one day you will — you should keep the ad accounts, the audiences, the creative files including working files, and a written record of what was tested and learned. Get it in the contract while everyone still likes each other.

Questions for the First Call

The checklist is diligence. These five questions are for the first conversation, and each is designed to be difficult to answer with a slide:

• "Which of our current ads would you kill first, and why?" Tests whether they looked at your ad library before the call. Most did not.
• "What would make you advise us to spend less?" An agency paid on a percentage of spend should still have an answer. Silence is also an answer.
• "Show us a campaign that failed, and what you changed." Paid social has a real failure rate. An agency with no failures to show has either no experience or no honesty, and both are disqualifying.
• "Who will make our creative, and where do they sit?" You are listening for names and desks, not "our network".
• "What will the month-two report show, before results exist?" Good agencies report leading indicators — test velocity, hook rates, cost-per-outcome trend — while pipeline matures. Weak ones show impressions and adjectives.

Red Flags That Should End the Conversation

• Guaranteed ROAS. Nobody controls the auction, the market or how fast your sales team follows up. A guaranteed return is not a forecast; it is a filter for buyers who do not ask follow-up questions. In B2B, where revenue lands months after the click, it is arithmetic fiction.
• Campaigns in their ad account. Covered above, worth repeating: if the account, pixel and audiences are not yours, every month you stay makes leaving more expensive. That is not a partnership structure. It is a retention mechanism.
• Vanity reporting. A case study built on reach and engagement with no revenue, pipeline or even lead numbers is telling you exactly what the agency optimises for. Believe it.
• No questions about your sales cycle. Anyone who proposes a plan before asking how long your deals take, and who signs them, is selling a template with your logo on it.

How to Run a Fair 90-Day Trial

Ninety days is the honest unit for B2B paid social: long enough for setup, testing and early signal, short enough that a mistake is survivable. A trial only works, though, if both sides agree in writing — before day one — what success looks like. That means a primary metric (cost per qualified opportunity beats cost per lead), a realistic threshold given your sales cycle, and the leading indicators you will accept as progress while pipeline matures.

1. Month one: infrastructure and first creative. Tracking rebuilt, accounts restructured in your name, first creative batch live. Judge the quality of their questions and the speed of shipping — not results, because there are none yet.
2. Month two: structured testing. Hooks, formats, audiences, offers. Judge learning velocity: can they tell you, specifically, what they know now that they did not know four weeks ago? "Still gathering data" is a permissible answer exactly once.
3. Month three: trajectory. Cost per qualified outcome should be moving in the right direction, with a credible account of why. Judge the trend, not the absolute — a £400 cost per opportunity falling 15% a month is a better sign than a flat £250.

Fairness cuts both ways. Give the trial a workable budget rather than a token one, resist redesigning your landing pages mid-test, and feed back lead quality weekly. An agency optimising blind towards leads your sales team quietly disqualifies is failing on your data, not theirs.

Take the Checklist Into the Room

Choosing a paid social agency is not really a procurement decision; it is a decision about whether the people making your ads and the people spending your budget will ever sit in the same meeting. If this checklist has sharpened what you are looking for, take it into every pitch — including ours. And if you want to see how an integrated create-and-distribute model answers all ten questions, ad account ownership included, talk to our paid social team. We will happily go through it line by line.