The goal is to promote science fiction and fantasy by providing a new way explore its variations. It's also provides an exercise in both practical programming and data analysis.
It's sort of a random walk. By default I work from award nominations and winners. I'm working to include everything I've personally read. I try and add coverage for at least one online market a month. I try to devote the occasional week to fleshing out a particular sub genre or publisher or cover artist or editor. Themed anthologies and year's best anthologies also provide great starting point. I keep a list of good recommendations I find online.