I have used thumbtack as a pro for two different home improvement companies i manage.
I have a good reputation and get plenty of jobs on other jobs websites but thumbtack is run by people who dont know how to generate leads. In fact they suck at it. Much of their revenue is made from reselling leads. No joke. Thumbtack buys a lead on facebook, then presents that lead on their news feed showing that the lead has contacted multiple contractors, often 3 or 4 at once which seems hard to believe. Multiple contractors will pay just to have a conversation with that one lead and try to win their business. I suspect many of the leads are fake, as I have offered them insanely cheap rates and not even got responses.
They allow you to take down your profile and remove it from the internet which is fair and why I respect Thumbtack.
It seems these days tech companies have low morals. What happened to the moral high ground we used to walk in the 80s and 90s. Nowhere to be seen these days as tech companies are blindly data driven and practice "get away with whatever you can" at all times.
That said, I will continue to use their service while hoping they fire the employee in charge of buying facebook ads and get a new guy or gal who can generate more leads for contractors and stop re-selling leads as their main stream of revenue.