Although it differs from spyware, adware often uses the same methods and technologies. Merchants initially were uninformed about adware, what impact it had, and how it could damage their brands. Affiliate marketers became aware of the issue much more quickly, especially because they noticed that adware often overwrites tracking cookies, thus resulting in a decline of commissions. Affiliates not employing adware felt that it was stealing commission from them. Adware often has no valuable purpose and rarely provides any useful content to the user, who is typically unaware that such software is installed on his/her computer.
Now most affiliate programs have strict terms and conditions on how the lead is to be generated. There are also certain methods that are outright banned, such as installing adware or spyware that redirect all search queries for a product to an affiliate's page. Some affiliate marketing programs go as far as to lay out how a product or service is to be discussed in the content before an affiliate link can be validated.