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.
So many webmasters overlook this critical component of a successful site. However, it is one that is easily corrected. A complete course in copywriting is outside the scope of this article, but to point you in the right direction, I would suggest that you start with "Tested Advertising Methods" by John Caples, followed by "Web Copy That Sells" by Maria Veloso.
Do they value and help their affiliates? Some affiliate programs do an exceptional job of communicating with their affiliates, notifying them of upcoming sales, offering marketing advice or tools, offering contents and prizes during promotions and more. These types of affiliate programs are a pleasure to be a part of. Ultimate Bundles is an excellent example.
This domain can work for people in two ways. One is to get sudden bursts of income by selling a certain product. The second part is selling a service that gives you recurring fees. This course on Affiliate Marketing Strategy for Stable and Recurring Income can be very helpful if your objective is the latter. At 5.5 hours and 56 lectures, this is very extensive and useful for those looking at mastering this subject. Details are available here.