The news items aired on radio will be broadcasted during morning and evening drive times. Here's a recent sample. If you recruit someone and you're rewarded for his sales, that's two-tier. However, read on . . . People tend to become blinded by greed.
Word spreads so fast that companies often fail to control idiot spammers.
It's a brave or foolhardy company which risks its reputation by getting involved with multi-tier marketing on the Internet. One example is Mark Joyner. He's an innovative thinker who doesn't blindly follow what other people are doing. I wasn't, anyway. It even might help a little, but don't expect miracles from it.