Update: the official word is to use the same bundle ID. See here.
So the problem is that if you already have a copy of Sound Studio, anywhere on your computer, and you open the Mac App Store, you can’t buy it in the App Store because it thinks it’s already installed. Which it is, in a sense, because the Mac App Store version and all the other versions of Sound Studio use the same Bundle Identifier.
Something which I had initially dismissed as a minor problem with the Mac App Store was what to set the Bundle Identifier of your app in the Mac App Store to. Panic blogged about bundle IDs today, and Gruber linked to it.
Turns out I should have picked a new, unique Bundle Identifier. Unique in the sense that it can’t be the same as the one from the previous version of the same app.Currently it’s com.felttip.SoundStudio. Something like com.felttip.SoundStudio.mas would have fixed it. But I never thought about doing that, because then it would mean that the preferences and document associations with the old app would not carry over to the Mac App Store version.
I had thought that Apple would fix this somehow, but here we are, one day after the Mac App Store opened, and people can’t buy my app because they already have a trial version.
The workaround is to delete every single copy of Sound Studio from your computer’s disks. Your preferences and presets will still be there after you buy the new version from the Mac App Store.
But there’s still the problem that people downloading Sound Studio from my web site have a copy with the same bundle ID as the Mac App Store. I need to change either the bundle ID in the Mac App Store, or on my web site download. I can’t change it in the App Store because that would mean removing the existing app from sale and offering a completely new SKU, abandoning everyone who already bought it.
So the only answer is to change the bundle ID of the trial and upgrade version that people can download from my web site, and send out an update with a new bundle ID (and that optionally searches and destroys all other copies of Sound Studio).
I think Apple should have made it clear as an explicit policy that you weren’t supposed to use the same bundle ID as the old version of your app, and rejected App Store submissions which failed that test. From my own search of apps that I already have that are in the Mac App Store, most developers used the same bundle ID, and now are running into the same problem.
Maybe Apple will have a solution. They could check that the installed versions also have receipts, instead of just checking the bundle ID. If someone copies an app that someone else purchased, the receipt is no longer valid on the copy, but the user can’t buy the app unless they delete all copies of the app. There’s probably a lot of other similar scenarios which need to be dealt with.
And it all comes down to my email support load. All these problems mean that I get more emails, and I’m trying to fix bugs and solve UI problems to minimize my support load.