I'm also a bit worried that the current wording (even if it's only one word) and presentation make it feel more competitive than you've intended it to be. I agree with Fenreliania above that a delta would serve the same purpose, possibly even better. Changing the term from "Rank" to something less immediately competitive like "Browse Position" could also go a ways towards improving this.
I certainly appreciate your desire to be transparent and help us measure our success, but I'd hate to see a change like this cause anxiety and stress in developers who otherwise wouldn't care about this sort of thing.