My impression is that Taxi is a service that pushes your music onto commercial ventures like television, advertisements, movies, etc. I'm pretty sure that if you watch enough TV, you can get an idea of what Taxi *typically* would look for.
From what I've heard, Taxi's greatest appeal would probably be if you either already had a large catalog of commercial-oriented music, or had the ability and time to create commercial-oriented music really quickly.
I agree that their website smells a wee bit of a "get signed quick!" scam. Their main page URL title for instance says "record deals" -- this makes me go, "huh?". Plus the listings are often sort of generic.
I was just re-reading my posts from last night and I can see where they may have come off a bit negative towards Taxi. I apologize for that and reiterate that Taxi does provide a service to those who are experienced and qualified for the task of creating top quality commercial-oriented music.