very Search Marketing, you can continue to build links and add a newsletter subscription box to capture the visitors e-mail, so you can advertise for ever ...
Maintaining top ranks of websites can indeed prove to be a challenging task, especially if the targeted terms are very competitive and chosen by tens or hundreds of other companies and webmasters as well. Continuing with the procedures and practices that have led to achieving top ranks is the solution and as you know SEO is an ongoing process, requiring contents plus links constantly.
Ranking in google can drop to a variety of reasons. Sometimes it is because google updates its ranking theory, thus improving or dropping your page rank, it can also be because google has decided to lower the ranking of websites linking to you, also some sites linking to you stop, for the best advice,
The best way to maintain ranking a website is to keep link building for your site to maintain its rankings on the search engines, If you are a larger business you might want to look into getting professional help and SEO.