For the low price of one dollar, I will predict for you whether you will win the lottery this week. I guarantee 99.9% accuracy or your money back. Think about the money you'll save by only paying me $1 on weeks when you would have lost anyway, when it costs much more than that to enter the lottery!
Now I'm going to spoil my business plan by telling you this: I'll just always answer "no", and it still works, because all I've done is set up a cheaper lottery with almost no payout (in part because, if you pay me for my prediction and you win anyway, I'm the least of your concerns).
The only problem is if someone pays me my dollar, I tell them "no win", then they pick the winning numbers without playing and sue me for the prize money they should have won.
Mokalus of Borg
PS - Of course, the only way to prove you "would have" won is to actually register the entry.
PPS - And it's probably not going to happen anyway, because that's how lotteries work.