Bitmixcoin.io did the same thing on this forum. They put 5 bitcoin into escrow with our user - zazarb. Once they gained some trust, they redeemed their escrowed 5 bitcoin and then scammed people, one person was scammed with 16 bitcoin. So, I wouldn't call that a good model.
I don't think the OP is bright enough to copy a scam. He claims his site will not require registration, and he claims he will figure out dispute resolution with no registration.
This is not a pre-planned scam using a known method like a ponzi. This is just an idiot who doesn't understand how other idiots scam.