Looks like I was wrong: today it hit #40 in free SF on amazon.com, #926 in all free books on amazon.co.uk, #694 on amazon.ca and #420 on amazon.in.
I’ll be interested to see whether the free weekend still has any impact after it goes back to paid tomorrow morning. It’s certainly given away far more copies than any previous free promotion I’ve run on other books.
Now it’s time to get writing the next book. Ok, it’s a prequel, so I guess that makes it a previous book :).