They make the lifestyle very tempting. The average business opportunity seeker is flat broke. Yes, some spammers are making a killing but they loose in the long run. For me I will choose the straight and narrow. The very thing you need to do business with anyone anywhere is the first thing that goes when you spam.
Credibility is what they loose.
There is nothing that will make you loose it any faster than spam. Most spammers will never get it back. Spam is out of the question for the serious internet marketer. Find a plan that works and then work the plan. It's that simple.