Datafeed? Some affiliate merchant operations offer a data file containing descriptions of individual products the merchant offers for sale. This data file includes product names, prices, descriptions, URL's for product images, and more. These are known in affiliate marketing as a "datafeed". With such a datafeed file, one can easily create a whole product catalog which you can then market any which way you want.
What I've found in my experiment is it doesn't require much (if any) marketing activity. All I've done is publish a site built dynamically from the datafeed. Even with little effort to publicize the web site, the search engines have indexed the site and people are finding the site in search queries and, most importantly, they are buying stuff. So, low effort expenditure, and income producing, sounds like a winner to me.
This set of pages is meant to hold design notes for the next generation of this technique. This round of work is meant to utilize the taxonomy features of Drupal to automagically build nicely indexed product catalogs with little work.