Keeping your web site visible then can become a full time job. There are thousands of search engines out there. Their rules are all different. Some are specialty tools and hone a search to a particular type of material. Others categorize web sites and require understanding of their catalog structure.
Some search engines sell top slots.
This creates a bias toward paying web sites when a result is compiled on a particular search tool. No one said that the results of a search had to be fair. You can be number 63,782,643 on a listing of 65,000,000. Rest assured that you will not gain a lot of traffic like that. To avoid being buried you must understand how the search tool works.