The scam issue constantly pops up in online marketing. The reason it does is because there are so many scams out there and many really do look legit. In some cases Payments may even be made to a few participants. But overall innocent people loose money or end up holding the bag when the scam becomes apparent.
So why if it is a scam would some participants get paid? To build the belief level in a cheering squad that will continue to push the hype the scammer has created. Even if the scam is not yet on the radar of agencies overseeing these things Such as the Federal Trade Commission, it is only a matter of time until they do hit the radar. By that time the scammer has distanced himself from the scam and left his cheerleaders to face the Firing Squad.
There are so many resources and watchdog groups it's hard to believe people still fall for it.
For more information on Pyramid/Ponzi schemes check out this transcript of a speech given to the Federal trade commission in 1998