I wrote for two sites at one point but i stopped for the same reason. The whole industry preys on teenagers who are hardcore hobbyists to write for free with the only benefit being attendance at these events and that for only the most talented ones. the rest get cast-off swag and old review copies of games. The amount of shit you have to sign to absolve the corporate suits of employee abuse is mind numbing.
Most of the managers are not too far out of their teens themselves. At 38 I had some little twentysomething trying to con me into 24 hour coverage of E3 on the website while they went and hung out at the parties and shit. They weren't even editorial staff, just the bean-counters and web statisticians.
Gamespy was a perfect example of the practice. Also, the new thing is to put up a game blog and invite others to "Blog" with them. If your "Blog" is good enough you get to be in the main crew where you, once again, are writing for free while one or two guys pull in scads of revenue. Destructoid.com and Kotaku.com are two examples (though i think kotaku will actually pay people who write on a weekly basis). At some point it'll all come crashing down (I hope).