Put a link on your website to the site of the vendor. When people click on that link and buy something on that other site, you will get money for it.
The affiliate link has YOUR specific ID in it for that vendor. You need to sign up and register for the vendor's affiliate program. You will be given a link that is just you. That is your affiliate link.
Don't forget to replace XXX or whatever needs to be replaced with your own ID ! This is a typical mistake. But usually, the sponsor has a script that changes everything and gives you the linkcodes with your ID already embeded. You just need to put this link on your web pages. So that potential customers can click on your link and if he buys, you get credited for the sale.
If you have never used affiliate links sign up at something like Tradedoubler or Commission Junction. From there you will find plenty of easy to follow examples. Good luck
I'd like to point out that affiliate programs can be quite tricky; especially for newbies like myself. The deal is there are a lot of companies with products you can promote. The catch is that they are marketing their selves. So, they have restrictions in place so that you cannot use their keywords in a PPC campaign. (They don't want competition!) Or they don't allow certain types of marketing...if you don't have a lot of TARGETED traffic coming to your website already for that product, you're stuck! Affiliate programs could be profitable if you have TARGETED traffic on your site that you'd like to monetize. Especially, if you can find products that compliment your own! Please comment on this post...I'm always learning.
Affiliate Marketing is an Internet-based marketing practice in which a business rewards one or more affiliates for each visitor or customer brought about by the affiliate's marketing efforts. It is an application of crowdsourcing.[citation needed] Examples include rewards sites, where users are rewarded with cash or gifts, for the completion of an offer, and the referral of others to the site. The affiliate marketing industry has four core players: the merchant (also known as 'retailer' or 'brand'), the network, the publisher (also known as 'the affiliate') and the customer. The market has grown in complexity to warrant a secondary tier of players, including affiliate management agencies, super-affiliates and specialized third parties vendors. Affiliate marketing overlaps with other Internet marketing methods to some degree, because affiliates often use regular advertising methods. Those methods include organic search engine optimization, paid search engine marketing, e-mail marketing, and in some sense display advertising. On the other hand, affiliates sometimes use less orthodox techniques, such as publishing reviews of products or services offered by a partner. Affiliate marketing—using one website to drive traffic to another—is a form of online marketing, which is frequently overlooked by advertisers. [1] While search engines, e-mail, and website syndication capture much of the attention of online retailers, affiliate marketing carries a much lower profile. Still, affiliates continue to play a significant role in e-retailers' marketing strategies.[2]