These sites promote the farce that venues have difficulty finding good talent. Actually the opposite is truer and these sites don't facilitate the reality that good artist who are talented, reliable, and hardworking sometimes don't look good on paper or video. A good video can mean that everything the artist had no control over panned out.
The biggest beef with the site is too many venues that clearly have no desire to book a metal band, children's performer, or blues act will take submissions from them. Venues should be held to a limited number of genres that realistically reflect their actual vibe.