Everyone has different expirences as I can see. It comes down to what business you get involved in and who is recruiting you. If one were to call you, or you call them and they offer you a position right away, stay away. Real MLM recruits want real people to invest and build their business under then, retention is very important. Its dependent on time and effort and treating it like a real business. 99% of MLM are not scams just do your research and find the real people in the industry, like Jon Budd or Mark Yarnell. They will teach you what it takes, not what they offer. We live in a life where people take in all this information and not enough time taking "action!!"
If you are a newbie, forget it! Chances are in 99% that you will not see any significant profit or even lose money. If you are good at marketing, pick any MLM that has a good reputation and (preferably) doesn't require upfront payments or other investments other than advertising. If you are an expert, you will probably succeed at any MLM program regardless... When it comes to MLM, the only winner is the company.