I hope that works, because I have two N9 16Gb under the same Nokia account. On one N9 the wallpaper I mentioned in the first post is already installed, but I could not install it on the second one.

In other words, I can at least confirm that paid Nokia apps are not dependent solely on the account. The interesting thing I noticed is unlike real apps, the wallpaper cannot be uninstalled either through Settings or Store. So I cannot test the IMEI theory by uninstalling it and reinstalling it without resetting the phone.

Edit: And yes, I agree installing wallpapers from the store is mildly stupid, especially paid ones. But this one looked good, was free, and was the first "app" I installed on my new N9.