In the offline business world, someone that refers a customer to a business is entitled to a referral fee. Referring customers to online businesses is called affiliate marketing. Thousands of businesses have established affiliate programs in order to capitalize on the fact that website owners are willing to promote their business in exchange for a fee. This fee is only paid if the customer actually buys a product or service offered by the business, but the fee is typically much larger than you'd receive from a PPC ad. Referral fees typically range from 1-50% of the price of the product or service. So, depending on the product or service that the customer buys, your referral fee can be quite substantial.
You may wonder how the business knows that you sent the customer to them? This is accomplished by using a coded link on your website that directs customers to the business. Coded links point to the business website in the normal manner, but they include a unique alphanumeric tag affixed to the end which lets the business know which affiliate directed the customer to them.
Often times third party affiliate sites manage affiliate programs for businesses. They act as sort of a clearinghouse, whereby businesses interested in having affiliates and website owners interested in earning revenue meet. The well know and highly respected affiliate sites are:
You can find nearly any product or service to promote at these sites. Visit these sites, create accounts, get affiliate links from businesses you want to promote, and place the links on your website.
After you've included ads and/or affiliate links on your website, the next step is to promote your website so that visitors will come to it.