What this page does and does not do
It describes three funding models structurally, and it does not tell you which model any named platform uses or what it charges. That is deliberate. Every platform publishes its own current fee terms on its own site, those terms change, and we were not able to read those pages directly, so we are not going to describe them from memory or from search results. Go and read the fee page of whichever platform you are considering. It is the single most informative page on any of these sites and it is usually two clicks from the "join as a trade" link.
What we can do is the arithmetic, because arithmetic does not need a source.
The three shapes
| Model | What the trade pays for | What the trade is buying | What it does to your quote |
|---|---|---|---|
| Membership subscription | A recurring fee to be listed, usually annual or monthly | Presence. The cost is the same whether the member wins one job or fifty | A fixed overhead spread across all of that member's work, so the per-job effect falls as the member gets busier |
| Fee per lead | A charge each time an enquiry is passed to them | Attempts. The fee is charged on the introduction, not on the outcome | The member has to recover the cost of the leads it lost as well as the one it won, out of the jobs it wins |
| Commission on the job | A percentage or margin taken from the work | Outcomes. Nothing is paid until something happens | Scales with the job, so the larger the work the larger the amount sitting inside the price |
Most real platforms are a blend. A subscription with paid promotion on top, or a lead fee that varies with the size of the job, or a commission model with a membership floor. The shapes are a way of reading a fee page, not a taxonomy anyone has to fit.
The arithmetic that matters, which is the second row
The per-lead model is the one worth thinking about, because it behaves the least like people expect.
Suppose an enquiry is distributed to four member firms, and each pays for it. Four fees are charged. One firm can win the job. That firm's price has to carry the fee it paid for the introduction it won, and across the year, the fees it paid for the introductions it lost. If a firm converts one lead in four, its advertising cost per job is four lead fees, not one. If it converts one in eight, it is eight.
That is the identical shape to paid search, which we have already set out with measured London numbers in what the sponsored result costs you. You pay for attempts and you recover from successes. The only difference is the unit: a click there, an introduction here.
It has one visible consequence for you, and it is not a price. It is how many people ring back. If you fill in one form and four firms call within twenty minutes, the model is working exactly as designed. That is a genuine advantage if you want competing quotes on a kitchen refit. It is a genuine nuisance if there is water coming through a ceiling and you want one van.
The subscription model runs the opposite way and is easier to live with. A fixed annual fee divided across sixty jobs is a small number per job; divided across six it is a large one. So the cost per job falls as the member gets busier, which means an established subscriber carries less of it in each price than a new one does. Nothing about that is visible from the outside, which is why a subscription-funded listing tells you very little about the price you will be quoted.
A commission model is the most transparent of the three in one respect and the least in another. Nothing is charged until work happens, so nobody is recovering the cost of failed attempts from you. But the amount scales with the job, so the larger the work, the larger the sum sitting inside the figure, and on a job that turns into detection plus repair plus reinstatement that can compound in a way a flat lead fee does not.