Search engine marketing recognizes that websites get a large amount of web traffic, approximately 30 percent, from Internet web searches. Search engines like Google, Yahoo, Bing and AOL create standards that serve as guidelines for developing search engine advertising. The 2 main ways of advertising using search engines are search engine optimization (SEO) and paid search advertising. SEO is the process of improving a website so that the content ranks highly on search engines. In paid search advertising, companies buy paid listings using chosen keywords. Most often the advertiser has a Pay-Per-Click (PPC) plan. Every time someone performs a query on a search engine, they will see both free, organic results and paid listings. Learning to use both types of advertising will increase traffic to your site. Learn how to use a search engine for advertising.