Rewardtables. A ponzi-scheme to invest in?

Rewardtables is a ponzi-scheme that shows you who is getting payed. The person on top of the table will get "pushed" into getting payed by other players buying a spot on the bottom. The cycle happens when all the spots are bought. I haven't bought a spot yet, but have heard is doing bad atm. Does someone use Rewardtables and if so, is it worth investing in a spot?

I use them and won't recommend them at all. Looks like ponzi.