Affiliate websites are one of the fastest growing wings of e-commerce. You can literally find thousands of affiliate partnerships to choose from. This is both good and bad news. The good news is that there are great affiliate deals to be found online that haven't yet been over-saturated by partnerships. The bad news is that there are affiliate partners out there that you shouldn't touch with a virtual ten-foot pole.
There are a number of steps you should take before signing up with an affiliate partner. First, you should read the affiliates terms and conditions. Too often, budding marketers skip over an affiliates terms. An affiliate partner may not allow for Google Adwords or other marketing avenues so make sure this is not explicitly laid out in the affiliates terms and conditions. If there are no terms of service, this should be a warning in itself. A reputable affiliate will normally have terms of service.
Payment is obviously a huge one. Make sure the affiliate has reasonable terms. Some affiliates, such as Amazon, only pay out after a set number of sales—you do not make a dime on the first, second, or even tenth sale. Other affiliates will pay out for each sale. The flip side is that an affiliate with a sales minimum may also have a better percentage payout. The best-case scenario is to find an affiliate partner that pays out for every sale and offers a good percentage.
This will be all for naught if the affiliate does not pay out in a timely manner. Try and not learn from experience, in other words, don't get burned. Instead, learn from other people's experience. Go to affiliate marketing forums to see if a particular affiliate has a good or bad reputation. The trouble here is that a new affiliate might not have a marketer base yet, and these affiliates usually offer the most attractive terms in order to bring affiliates in. Use some common sense—if the affiliate's site is well designed and they offer a good and useful product, you could try and test the waters.
On that front, it is sometimes a good idea to find an affiliate partner that is not overly saturated. If you offer a service that can't be found on every other web page, it can lead to a better sales rate. However, once again there's a flip side: if it's a virtually unknown site, it's harder to build up buyer's trust, as compared to well-known affiliate programs like Amazon or the Discover card. A lot of the onus falls on you—if your site is well designed and well managed, buyers will trust your affiliate links.