If you have a website, engage in email marketing, or use browser extensions, you can join in an affiliate program that can earn you revenue from the traffic that comes to your site.
As an affiliate, your web site essentially partners with an online merchant or advertiser. When you join an affiliate program, you are able to put links from participating merchants anywhere you want on your site. These links typically come in the form of banners, text, and a number of other, more sophisticated types of links. The HTML code that you require for these links is supplied to you by an affiliate network program that administers affiliate programs.
There is no cost to you to become an affiliate. The merchants pay a fee for submitting their advertisements, offers or links with an affiliate network program.
You are also entitled to join as many programs as you wish. As an affiliate you should generally not agree to an exclusive arrangement with any single merchant. However you do want to be selective in the partners you choose and find those that best suit the audience at your web site.