My site gets about 25-30 Googlebot crawls per day. Usually there is a plus some number denotation after it in my statistics section, i.e. 25+2. The +2, as I have noticed whenever I wake up the next day and check, usually turns out to be the number of newly indexed pages on that particular day.
Whether that's true, I don't know, but for a newbie "webmaster" such as myself, it's been a pretty consistent theory.
