Never had any problems using it, including MLB and NFL games (maybe a concert or two?). Some sports teams use them as a direct vendor to unload extra tickets, but it is also like Amazon Marketplace in that anyone can sell their tickets there. StubHub also gives you an 800 number to call if you are denied entrance with tickets purchased there for any reason. I've never had to use it, so I'm not sure if they could actually do anything if you really needed to get in the concert...