Sellers are scrambling to understand how eBay will rank listings and what the best practices for great search placement are ultimately going to be. As always, eBay hasn't released calculation-by-calculation details, but they have been relatively open about the concept behind Cassini and the kinds of data that will play into search outcomes.
Using these as a guide, it's a small step to come up with best and worst practices for Cassini and your search placement on a new, Cassini-enabled eBay.
Make Best Match Work for You
Understanding Top-Rated Seller Status
Monitor Your Seller Performance Rating