Paid advertising — this method requires an effective combination of ad copy, graphics, and a highly-clickable link. Unlike more traditional affiliate marketing strategies, paid advertising (through pay-per-click ads) earn you money regardless of whether a reader buys the product or not. Services like Google's AdSense make this quick and easy for you, and can even supply you with an advertising code.
Of course, the number one thing you want to look at is the commission rate. What percentage of the customer’s payment will you receive? In some cases, there is a flat fee for every sale made, and sometimes you will get a percentage of the total sale. Keep your eye out for "percentage of commission" sales, as this means that you're not taking a percentage of the total sale, but rather a percentage of the company's commission.
Prior to that group, they had an online community for teachers looking for lesson plans. That probably sounds pretty random, but it's crazy the type of communities you can build and rally people around. If it's something that you're passionate about yourself and you want to connect with others that have that same passion, then an online community is something you should definitely consider.
The problem with affiliate marketing, like many other home business options, are the so-called gurus and get-rich-quick programs that suggest affiliate marketing can be done fast and with little effort. Odds are you've read claims of affiliate marketing programs that say you can make hundreds of thousands of dollars a month doing almost nothing ("Three clicks to rich!"). Or, they suggest you can set up your affiliate site, and then forget it, except to check your bank deposits.