Can you really make money on MLM(multi level marketing)?

There are so many friends of mine joined this so called MLM business. They promise to make money fast in this business. Example of this are aim global, emgoldex, UNO, success200, and so on.

Well in my own opinion MLM is not a business it is a job. Because if you cannot recruit a so called downline you cannot earn money.

What is MLM(Multi Level Marketing)?

As per wikipedia,

"Multi-Level Marketing (MLM) is a marketing strategy in which the sales force is compensated not only for sales they generate, but also for the sales of the other sales people that they recruit. This recruited sales force is referred to as the participant's "downline", and can provide multiple levels of compensation."

I don't like the design of this kind of marketing because if 1 person earn money 2 or more person loss money. 90 % of my office mates are member of 1 MLM only 3 of them makes money the rest regret that they put money on this.