For agencies · Last reviewed 1 July 2026 · Worked numbers are illustrative. Substitute your own.
Agencies are meticulous about their clients' numbers and strangely casual about their own. Ask one what a lead costs their client and you get a spreadsheet. Ask what a new client costs them and you get a shrug and something about referrals. The fix is one metric, applied to every channel you use: cost per client won, set against what a client is worth. Here is the framework with honest numbers.
Deliberately conservative example: a £1,200 a month retainer that lasts 18 months, at a 50% gross margin. A £4,000 one-off build at 40% margin. Your real figures will differ, and that is fine. The point is to have a number, because every channel below should be judged against it.
Highest close rate of anything on this list, and effectively free. The catch is structural: referral volume follows the work you did last year, not the pipeline you need next quarter, and it dries up at precisely the moment you need it most. Systematise the ask at project close, look after the accountants and photographers who send you work, and treat referrals as a dividend rather than a plan.
The marketplace model works by selling the same enquiry to several agencies at once, which means you fund the listing fee, the lead fee, and then a price war against three lookalikes. Once you compute the fees against a realistic win rate, cost per client won is usually far higher than the listing price suggested. Fine for marginal volume. Expensive as a foundation.
Clicks on commercial web design terms in competitive UK cities are not cheap, and the click is only the start. Multiply through your landing page conversion, your qualification rate and your close rate, honestly, and cost per client won lands in four figures more often than anyone admits. It can absolutely work, but it rewards a sharp niche offer and punishes a generalist arriving cold.
The costs land now and the returns arrive quarters later, then keep arriving. It is the best long-term channel and the worst answer to a quiet month. It also only compounds if you publish to a standard that earns rankings. Half-hearted content is pure cost.
Outbound is the only channel where volume is a dial you turn, which is why deliberate growth plans lean on it. Its economics come down to a single question: what does it cost you to produce one qualified, evidenced opportunity? Done by hand, the research is the expensive bit. Finding businesses worth contacting, checking each website properly, digging out a contact, writing an opener that proves you looked: the best part of an hour per genuinely qualified prospect, at whatever your hour is worth. The sending costs nothing. The research is everything. Compress that hour to minutes with tooling and the channel's cost per client won drops by an order of magnitude. That is the economic case for audit-led prospecting, and it is the job Weakspot was built to do. Against the client values above, one win pays for years of it. The arithmetic is not close.
No single channel is the answer. The agencies that grow on purpose run three at once: referrals harvested properly, one compounding channel funded with patience, and one controllable channel, almost always outbound, run to a measured cost per client won. The measurement is the strategy. Know your acquisition cost per channel and you can spend with intent. Skip the measurement and you are guessing in every direction at once, which is exactly what you would tell a client to stop doing.