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.
Paying interest and referral commissions only makes it a Ponzi if you are too thick to understand what a Ponzi is. This has been explained to you countless times before but as always you ignore that and repeat your false claims.
https://www.investopedia.com/terms/p/ponzischeme.aspWhat Is a Ponzi Scheme?
A Ponzi scheme is a fraudulent investing scam promising high rates of return with little risk to investors. The Ponzi scheme generates returns for early investors by acquiring new investors. This is similar to a pyramid scheme in that both are based on using new investors' funds to pay the earlier backers. Both Ponzi schemes and pyramid schemes eventually bottom out when the flood of new investors dries up and there isn't enough money to go around. At that point, the schemes unravel.
Freebitco.in uses a small part of the income generated (profit) to pay interest and referral commissions and does not have any similarity to a Ponzi.