Drupal Pro book cracks Amazon Top 100

About a week ago the new Pro Drupal Development book started shipping, and today, the book cracked the Amazon Top 100. And we're not talking about the top 100 computer books here, we're talking about the top 100 bestsellers.

Drupal pro amazon rank
Drupal pro amazon rank

I'm still waiting for my copy to arrive, and rumor has it that Apress, the publisher, already started making arrangements for a reprint.

That ranking might be short-lived but still ... can someone tell me what is going on here, because this is just plain nuts. I didn't expect that to happen either ...