I probably check the amazon page of my book more than I should Here's kind of what happens in the course of a week:
Oh, #9, nice! (the ranking in the category of Knitting books on Kindle)
Drats, down to #12
Uh-oh, #19 but there's a nice new review.
Whew, back up to #9
Wow, #5? I should go check the sales stats too.
Uh-oh, a 2 star review?