How's the book doing?

Friends and colleagues are politely asking me "How's the book doing?" - BLEEDER, that is - in terms of sales. The polite answer is 'there's really no way to tell, especially this early.' The title was released 4 weeks ago and today its Amazon.com ranking was 122,000 (at about 7:30 pm Central). I guess that's pretty good since Amazon lists 3.5 million titles. The rankings are updated every hour at Amazon, and hardly anyone has figured out how to translate the erratic rankings into real sales numbers. There is a terribly expensive computer program that publishers use to track the numbers, but they are guarded with the figures and authors rarely learn the sales figures until quarterly or semi-annual royalty statements arrive in the mail. So I just do the next thing and don't think about it, except to note that Amazon last week said the title was out of stock and more were being ordered. But I wonder how many they order? 5? 50? It's a mystery.