Your question caught my attention. I sell a nonfiction Kindle and CreateSpace POD on Amazon.com .uk .de .it and .es .... once I uploaded to Amazon.com, the ebook version was listed after a bit on the European Amazon pages. I just took a look at Amazon.ca and was surprised to see that it wasn't listed there. I'm speaking in the Yukon next month and when I let the people that had signed up know about the book, I had a bump in sales.
Searching on Amazon.ca for Kindle books lists only 147 books. It tells me that Canadians shopping for Kindle books shop on Amazon.com
Wish I could tell you more–I don't get it.