I'm not gonna bother looking up the details of this one, but I will say it in a general manner. You collecting any money at all requires the tiers below you to fill up entirely. Chances are, unless you are in the top 3 or 4 tiers, they will never fill up.
But the time you start to get towards the 4th or 5th tier, there needs to be a couple hundred people to sign up so that the first FEW people get their money (which is funny, because they collect the most, but had to pay the least). Which means that those people on the 4th or 5th tier have to wait for a few THOUSAND people to sign up before seeing theit money get returned. By that point, you are probably somewhere on the 8th-11th tier, and those tiers require that a number of people that will never be reached sign up. What usually happens at this point is that the site finally gets busted, goes offline and totall screws everyone that hasn't collected more than they already did, if they do manage to stay online, however, you will soon realize that you need more people than have internet access in the world to sign up to manage to get your money.
Like I said, the few people that benfit from this game are on the 3rd teir max, and those are pretty much friends on the person who created it (or an alias for the person so they collect even more money.)
If you've got $25 that you wouldn't mind throwing away, go for it, but don't expect a single dime back.
My cousin sent my a "pyramid scheme" a while back that was really fun, instead of using money or electronics, you used post cards. It was the classic "six people on the list" where you send postcards to all six of them, then you give the list to as many people as you can, except you bump the person that is number one off, put your name at the bottom and then geta bunch of post cards from around the country. It cost me less than 10 dollars and was pretty neat to see some of the crazy postcards some towns have.. I think I got somewhere around 50 post cards. 🙂