A challenge with a lead-based commission structure is fraud prevention. If the form is easy to complete and the payout high enough, a dishonest affiliate can determine ways to auto-fill that form and collect commission on bogus leads. To prevent this, you would need a dedicated affiliate manager to police the quality of inbound leads. Warning signs include multiple leads originating from the same IP address, or patterns in data entry such as spelling variations on a single name — such as “Jonathan Smith,” “Jon Smith,” and “J. E. Smith.” When you detect fraud, boot the affiliate from the program immediately, and inform the network. And don’t forget to reverse any recorded leads associated with the bad affiliate.
When I was a child, my school would have fundraisers that involved us going door-to-door to sell magazine subscriptions (magazines were glossy, soft-cover publications that would be mailed to a subscriber’s house on a weekly or monthly basis). I didn’t realize it at the time, but I was right in the middle of an affiliate marketing scheme. The magazine companies had products they wanted to sell. Schools had the ability to sell these products. And for every subscription sold, the magazine companies gave a slice of the proceeds to the school. (In this example, there’s actually a secondary later of affiliate marketing; the schools effectively outsource the actual selling to the students, in exchange for prizes that come with meeting certain sales figures.)
Spam is the biggest threat to organic search engines, whose goal is to provide quality search results for keywords or phrases entered by their users. Google's PageRank algorithm update ("BigDaddy") in February 2006—the final stage of Google's major update ("Jagger") that began in mid-summer 2005—specifically targeted spamdexing with great success. This update thus enabled Google to remove a large amount of mostly computer-generated duplicate content from its index.
In November 1994, CDNow launched its BuyWeb program. CDNow had the idea that music-oriented websites could review or list albums on their pages that their visitors might be interested in purchasing. These websites could also offer a link that would take visitors directly to CDNow to purchase the albums. The idea for remote purchasing originally arose from conversations with music label Geffen Records in the fall of 1994. The management at Geffen wanted to sell its artists' CD's directly from its website but did not want to implement this capability itself. Geffen asked CDNow if it could design a program where CDNow would handle the order fulfillment. Geffen realized that CDNow could link directly from the artist on its website to Geffen's website, bypassing the CDNow home page and going directly to an artist's music page.