Advertised a nice little handyman job on one of the bigger of these sites last autumn. Had one guy ring up within a few hours, arranged meeting. He missed it. Arranged another meeting, made it, saw the job, agreed to do the work.
Didn't see him again for 2 months, rang him, got promise to start next day.
That was another two months ago. Job's been done by another now.
Hardly a scientific basis, but as a study of 1 of 1, am not impressed
It's a good idea, and only takes a minute to list a job and can find you a builder. But it's only the first step of selecting a tradesman.
In this area, most good one-man-band tradesmen are always busy even during this recession. It's the old saying; "If he's got time to be advertising, he's either very new or crap. Probably crap."
One of the most valuable things I have in my role of maintenance manager, is a contact list of good trades. I've got two good plumbers, two good sparks, a superb drains expert and landscaper and a good (but expensive) general builder. I make sure I pay their invoices promptly.