You completely misunderstand me. If incase this was a scam(not saying it is), then it would be more profitable for you to enroll more users during the exit, as a month of sig campaign, may just help increasing the site traffic tremendously. But escrowing 1/4th of the amount, is something a scammer would not be inclined to do, as the whole sig thing might just fail, and paying out 1/4th might just be a loss for him.