good point! "a surprise packet". In those websites no one is allowed to reveal his/her identity... And how can you trust someone you can't see real past works as freelancers are only allowed to upload some pictures and text for their portfolio.

IMHO The review and star rating system in that websites seems to be failed as almost anyone has 10/10 rating and reviews are copy/pasted copies. So these things can not act as a mean of trust between two parties.

It seems to me transparency is the way to go.