Even “featured results” slots are separate from the actual results that search engines offer; you cannot buy your way to the top of the rankings. If you have the money, you can purchase a top spot, but your audience will know that you paid for it, making it less effective.
Phrases and keywords are only one of many ways you can optimize your website ranking. Links also work: off-site links to your site, links to other pages in your site, and links to other sites. An excellent technique to have other sites link to your site is to trade your link for theirs.