I'm pretty sure there's an algorithm for the hottest hubs that isn't as straightforward as one would think. Sometimes I've got hubs in the first few pages of hottest that are surprising to me (since I have other new(ish) hubs that are getting way more views and AREN'T appearing there). No doubt, it's a mix of hub age, hits from OUTSIDE of Hubpages, number of comments and a number of other factors. This I DO know, their appearance on the front page(s) isn't solely a result of sheer number of views.