Here are some possible reasons:
Tupperware and Avon
are examples of two companies compete against their own distributors. In
other words, they each sell their products through other channels, e.g., retails
outlets, online, corporate sales.
It's hard enough sometimes to compete against
other companies with quality products, let alone compete against your own
company!
Any Company Under 5 Years Old -- The failure rates of even very good companies is so high in the first five years that it is too much risk for the average network-marketer to take. There are promising companies, which are probably worth the investment for someone with network marketing experience and extra funds he or she can afford to lose.
I Haven't Heard of It -- Therefore, if you are a distributor for an established network marketing company, use the form on my Contact page to tell me why I should include it. I might very well agree with you and you can be the first distributor listed on the Distributor Directory for your company.
Wild, Unsupported, Pseudo Scientific Claims -- In the health and wellness area in particular this is a major problem. While I might not agree with the efficacy of all the nutritional products sold by the health and wellness companies listed on Best-MLM-Opportunities, they by and large sell quality products without extravagant claims. Disagree? Tell me why.
Use Questionable Sales and Promotion Approaches -- The best example of this is Amway/Quixtar. Now I know there are lots of Amway fans out there and I don't think the company is "evil." However, it's hard to avoid the fact that they hurt our industry with their high-pressure tactics and training-materials-as-profit-centers strategy. "Amwayed" has become a verb for a reason.