Write Content
Add content to cover the keywords related to your product. There is no limit to the amount of content pages you can add to your site.
Linking
To increase the relative importance of your webpage you should acquire inbound links from other websites. This is a time consuming and expensive task. But it gives your site staying power in the search engine rankings.
Measure Results
How many visitors, how many "sales", most popular pages, most popular keywords, .. When you know what works , just do more of it, and phase out the things that do not work.
Change negatives
We prefer to put badly converting pages in a online "archive" rather than deleting them, search engine algorithms change constantly. Just like fashion things come and go..and come again. Also products that you no longer carry can send a searcher to a viable alternative.
Add/ Change Content
Keep adding content, keep expanding your keyword and key-phrase range and try different densities, inbound link terms.
By adding content you will eventually have something for every searcher. And that will solidify your position in the search engines.
