The advertised price is a per-lead price
Marketplaces charge per lead, not per job. Reported prices vary widely by trade and metro — cleaning at the low end, HVAC and roofing several times higher, large remodels higher still. Neither Thumbtack nor Angi publishes a rate card, and prices move with competition in your category and area, so any figure you read is a range someone assembled from contractor reports rather than a published tariff.
That is worth saying plainly, because most articles quoting exact per-lead prices are quoting each other.
The number that matters is cost per booked job
Divide what you spent by the jobs you won. If leads cost $50 and you close one in ten, each job cost $500 in lead fees before you turned a wrench. If you close one in five, it cost $250. The close rate moves the real price more than the lead price does.
This is why two contractors on the same platform, paying the same per lead, can reasonably disagree about whether it works. They are not describing the same channel — they are describing their own close rates.
Where the close rate actually comes from
On a shared marketplace the request goes to several businesses at once. You are not being evaluated against an abstract standard; you are being compared to whoever else replied, and to how quickly.
Which means the close rate is not a fixed property of the platform. It is partly a property of your response — and that part is the only one you control. Raising it lowers your cost per job without renegotiating anything.
A calculation worth doing once a quarter
Take one platform, one trade, one month. Add up lead spend. Count jobs won that came from it. Divide. Then compare against your average job value and gross margin — not revenue, margin.
If lead cost per job exceeds the margin on that job, the channel is losing you money no matter how busy it makes you look. That happens more often than people expect on low-ticket work with high lead prices.