Well, being lucky and winning jackpots and stuff is one thing but wagering with1000 bitcoins or even keeping this amount on the centralized platform (no matter how much trusted it is), is super risky. I would not even imagine to wager with such high amounts. Sometimes i feel that in order to become rich in gambling, you need to be rich from behind so that you can wager more and win more. Also risk of losing is always there but those who take big risk, won't care much about big losses too.

No matter how rich this user is, one should always know the measure and stop in time, especially regarding gambling. And if we keep in mind the house of edge on the freebitcoin site, it's hard to believe that this user is still getting a profit rather than a loss.
One way or another, the presence of such a user is very profitable for freebitcoin both in terms of profit and attracting additional attention to the site.