Well you gotta realize that MLM organizations and pyramid schemes are almost identical in structure. The main difference between MLM(network marketing) and pyramid schemes is that anyone at any level or the organizational pyramid can "hypothetically" make money, at least in the early stages. When the organization reaches a certain population level, though, it becomes nearly impossible to make money by signing up new members. At that point, your simply a salesman. And since you're paying more for the products than you can make selling them, without those new membership bonuses you're just standing in quicksand.
By the way, your buddy is pitching it to you just to make a quick buck for himself.