Actually it IS a ponzi if you think about it.  Since ALL the BTC flows to the top (that would be the site owner, TheQuack,  and some referral accounts along the way which indeed forms the triangle/pyramid formation of a pyramid which is a form of ponzi) and it can only continue if it has NEW money coming in,  then it is,  by definition, a Ponzi/Pyramid scheme.

What makes it a ponzi?  The offer of an annual return.   If it DIDNT have that,  it would be a pyramid scheme.