Big time doubts, too high rate and no explanation what will they do with the money.
actually there is an explanation on the site if you checked it out. and someone even explained it above your comment
http://i.imgur.com/Cgugb23.jpgnow lets talk about whether it is a Ponzi scheme or if it is going to be the run away plan.
It is not Ponzi scheme. @wetsuit show in public their Bitcoin mining address, their power and pools where they are mining.
You can read about that in Freebitco.in main thread:
https://bitcointalk.org/index.php?topic=320959.msg18109501#msg18109501