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.
Often, what happens is that we run into unscrupulous Internet Marketers (IMs) who have less-than altruistic intentions of extracting money from you rather than helping you to make it. However, this isn't something new. People have been falling for networking marketing, pyramid schemes, and affiliate marketing scams since before the start of the net.