1. Not cloaking affiliate link: It is important to cloak the affiliate link using link cloaking software. It is available on the Net, both free and paid versions. Alternately, you may use URL shrinking services such as www.TinyURL.com. When you enter your original affiliate link URL you will get an entirely different output which is small, neat and clean. However, when the visitor clicks on the link they will be taken to your affiliate link website. A naked unprotected link is vulnerable to misuse sometimes. Imagine the money lost even if it is only for 10 percent of abuse.
2. Not checking the working of the link: The simple act of checking can save you tons of money. It is possible there is a spelling mistake, or the full link was not copied and pasted properly. Such habitual precautionary measures can avoid you losses.
3. Using the wrong affiliate link: Newbie affiliates blindly sign up for several affiliate programs and sometimes forget to use right link. This means the link takes them to the wrong landing page of another affiliate program. Which means loss of visitor.