Get-rich-quick schemes and fad weight-loss diets are naturally popular because they satisfy the id while also attending to the super-ego. The ego's job is complete when it sees something like this. The appeal of "fast'' stems from the innate desire for instant gratification, so beware of what seems too good to be true (they often are) when you're looking to make money quickly. Be wary. Listen to the conversation deep within the confines of your mind and do your best to tame the proverbial beasts.
The problem with affiliate marketing, like many other home business options, are the so-called gurus and get-rich-quick programs that suggest affiliate marketing can be done fast and with little effort. Odds are you've read claims of affiliate marketing programs that say you can make hundreds of thousands of dollars a month doing almost nothing ("Three clicks to rich!"). Or, they suggest you can set up your affiliate site, and then forget it, except to check your bank deposits.