tracking my book sales before there's a book

My (soon to be published) novel doesn't have a cover or even final contents yet, but I'm thrilled to see that it already has a listing on Amazon. You can't buy it yet, but you can pre-order. At least a few kind readers (and my mother) must have one-clicked already because my sales rank went from #172,987 yesterday to #151,748 today. (The smaller the number, the better the sales.) I know the ranking is meaningless, but I find the uptick (or downtick) irrationally gratifying. All those years scoffing at data geeks in meetings--now I'm the sucker for numbers.