Contrary to what some web site owners believe, it is not high search engine listings that generate sales - it is combination of compelling copy and easy navigation. So you want the site to be easy to get around and you want the copy to sell.

But to get the sale you have to be found and in order to be found easily in search returns you need to have keyword rich html text. So search engine friendly content and online sales copy have to be married in order to form a winning combination.