The art of bringing traffic to your websites is called Search Engine Optimization (SEO) because while there are other ways other than leveraging google and other search engines to bring traffic to your site, they are much more difficult and/or expensive to keep going.

Think about the way you use the Internet.  Can you use the Internet to find the names of the first 10 Vice Presidents of the United States?  The answer is probably yes if you are accustomed to using search engines, otherwise it is like wandering through a random assortment of books.

The search engines like Google, MSN, WebCrawler, Yahoo and the many others that are too numerous to list here for our purposes want to list your site, but they want to control what position your site holds.  Position doesn't sound that important, but it is well established that if you search for a site the odds are that if it isn't in the first 30 in the results then it might as well not be there at all and top 10 is much more important than anything else.  The good news is that it is very hard to game the system.  Even if you manipulate one of the engines the others don't use the same measures.

The effort to get into the top 10 (or even the top 30) for a set or specific search engine is the basic principle of SEO.  Succeeding in this task is very valuable as it can mean thousands or in some cases even millions of visitors to your site at no incremental cost to you.  If it were easy everyone would be doing it so don't assume that it is just 3 clicks and done, but it is a sea of opportunity so even though the rewards are huge it is not mission impossible.