Cost per click was more common in the early days of affiliate marketing but has diminished in use over time due to click fraud issues very similar to the click fraud issues modern search engines are facing today. Contextual advertising programs are not considered in the statistic pertaining to the diminished use of cost per click, as it is uncertain if contextual advertising can be considered affiliate marketing.
Affiliate marketing currently lacks industry standards for training and certification. There are some training courses and seminars that result in certifications; however, the acceptance of such certifications is mostly due to the reputation of the individual or company issuing the certification. Affiliate marketing is not commonly taught in universities, and only a few college instructors work with Internet marketers to introduce the subject to students majoring in marketing.
In April 2008 the State of New York inserted an item in the state budget asserting sales tax jurisdiction over Amazon.com sales to residents of New York, based on the existence of affiliate links from New York–based websites to Amazon. The state asserts that even one such affiliate constitutes Amazon having a business presence in the state, and is sufficient to allow New York to tax all Amazon sales to state residents. Amazon challenged the amendment and lost at the trial level in January 2009. The case is currently making its way through the New York appeals courts.
In 2006, the most active sectors for affiliate marketing were the adult gambling, retail industries and file-sharing services.:149–150 The three sectors expected to experience the greatest growth are the mobile phone, finance, and travel sectors. Soon after these sectors came the entertainment (particularly gaming) and Internet-related services (particularly broadband) sectors. Also several of the affiliate solution providers expect to see increased interest from business-to-business marketers and advertisers in using affiliate marketing as part of their mix.:149–150
Affiliate marketing is commonly confused with referral marketing, as both forms of marketing use third parties to drive sales to the retailer. The two forms of marketing are differentiated, however, in how they drive sales, where affiliate marketing relies purely on financial motivations, while referral marketing relies more on trust and personal relationships.