Comment 2 for bug 1020118

It is indeed a common support issue, and it's generally a pain to recover from -- especially if the user figures out the issue on their own and tries to merge their Launchpad accounts.

I can think of three UI changes which should reduce this issue:

 - Add a "log out" button, so they can change accounts.
 - Add something in the UI which shows which account they are currently using.
 - When USC starts, ask the user which account they would like to use. This may be unnecessary most of the time, but can be important when redeeming a coupon so the user has a chance to choose the account before redeeming the coupon. So, perhaps only do it during a coupon-related operation?

For that last one, I've seen a similar interface in some Android apps, where it will ask the user to select an account from the list of known Google accounts. However, Android has facilities to track accounts in the OS, so it's significantly easier to deal with there.