It is most definitely a scam! And I would caution anyone who uses the word "probably" - that you might get taken in by it. The only way to avoid these scams is to use the word "definitely".
I mean come on... they charge something like $200 to sign up PLUS you have to bring in two or three more people under you at the same time who also pay $200. Then they charge $400 a MONTH! $400 so you can get commission-free trips and keep the total fare. But guess what? THEY DON'T HAVE ANY TRYPS!!! So these guys, these idiots are paying $400 a month for absolutely nothing!