Well every freeroll I have played at hasn't been easy. I have cashed a few times. I play a freeroll on Bodog that always has no less than 4000, which is the max. I have placed a few times, the top 99 cash, I have never gotten to the top 10, which is my goal, but have gotten decently close.
Freerolls arent really easy to cash, because they are, well free, so everybody wants to play them. Why not, its a great investment. You pay $0 and possibly get something in return. It just sucks when you play for 5 or 6 hours and just miss placing! ....
You best bet is to play one around noon, or two or three. This will eliminate alot of the yahoo's, and you will more than likley be playing with a decent crowd, it might not be as full either. I notice the later it is you play, the more donkeys. Don't get me wrong, alot of really good, and online pro's play at night, because of the same reason. They can make more money.
If you can place, then play a SNG or a $10 Max table, build up your bank roll, then start playing in the tourneys that you have to buy-in at. There isn't half as many people in these.