*Well, in Fantastic Planet since they opened shop in 2005....
This sf/f bookstore in my hometown (Perth, Australia) has just published a list of their top 100 bestsellers. And there is Heart of the Mirage at number 74. You can see the whole list here, but before you look, see if you can guess any of the top ten and let us know in the comments section! Two of the ten are Australian authors.
71...Where's My Cow?, by Terry Pratchett
72...Iron Council, by China Mieville
73...Blue Dragon, by Kylie Chan
74...Heart of the Mirage, by Glenda Larke
75...The Rabbits, by Shaun Tan and John Marsden
76...Chasm City, by Alastair Reynolds
77...Spin, by Robert Charles Wilson
78...Geodesica Descent, by Sean Williams
79...The Android's Dream, by John Scalzi
80...Ender's Game, by Orson Scott Card