I've written several modules for use on my DNN sites and put a coule of them up for sale.

The first of them is a Cipher Solver, in use here. A fun little time waster cerebral exerciser designed to keep people coming back to a site.

The second is designed to enhance your site's revenue stream on Snowcovered: CommissionJunction Interface.

Commission Junction is a way to, well, let me quote their web site:

Drive quality results and extend your reach by partnering with affiliate marketing's most productive network of publishers. Further increase sales by complementing your customized affiliate marketing program with a fully-managed and integrated, comprehensive search engine marketing solution.

What it really means is that you can offer your users products from top line vendors across the world and get a commission for the sale. No matter what your website, you probably have items that you know would be a benefit to your users, from tech tools to books to MP3s. Why not generate revenue with your knowledge? All you need to do is create an account with them and set up a developer's key, you'll be all set to start selling on your website.

You can search by keyword, UPC or ISBN. You can set a default search to show up and allow your users to enter their own searches or lock it down so they only see the search you set up.

Adding this module to your DNN site is quick, easy, and a good way to start generating revenue outside of the typical DNN store.