WordPress is a great choice for anyone building a website, although personally I simply love Drupal and that's the one I use, I know that MANY people love Wordpress the same way I do love Drupal, and that's fine. One advantage of Wordpress over Drupal is the number of plugins there are.. Impressive!
Well cbproads has a Wordpress plugin which allow you to create Clickbank niche stores very easily, displaying all available products in a specific niche. If you want to have a look at an example of all the niche storefronts they allow you to use already, go to my top list devoted to them, here:

Niche Marketing is a way to get ahead by targeting very tight niches and selling very specific products and services. Here are the top 5 niche marketing tips to help you succeed in this tough field, specifically in finding and ranking these niche sites with SEO and common sense tactics that can get you to rank on page 1 of Google SERP

Many writers focus on a niche but fail to recognize the benefits that a site like Squidoo can offer to help enhance the writer's domination in that niche as well as helping them to profit from it financially.