Apple makes some grand claims on their web site:

Thousands of apps. One simple way to get them.

With the Mac App Store built into OS X Lion, getting the apps you want has never been easier. No more boxes, no more discs, no more time-consuming installation. Click once to download and install any app on your Mac.

Keep your apps up to date.

Since developers are constantly improving their apps, the Mac App Store keeps track of your apps and tells you when an update is available. Update one app at a time or all of them at once, and you’ll always have the latest version of every app you own.

That sounds wonderful – but it’s a lie!

Some developers aren’t happy with providing free app updates to existing customers, so they publish updates as a discrete new app. This means that existing customers aren’t able to receive the update without purchasing the app all over again. Even worse the developer sometimes removes the legacy app from the App Store entirely, so it’s not available if you want to re-install it.

Buy, download and even re-download.

You can install apps on every Mac authorised for your personal use, and even download them again. This is especially convenient when you buy a new Mac and want to load it with apps you already own.

Again, not true!

If a developer decides to withdraw an application that you previously purchased from the App Store then it’s gone and there is no mechanism to download it again.

I discovered this anomaly after I tried to install an app that I ‘owned’ onto a new Mac. After a bit of head scratching it was apparent that the developer had published a new version of the app just a few months after my purchase. Since I couldn’t re-download my purchased app I took it up with Apple Customer Support..

This is their email response:

I certainly understand how recent difficulties might have been frustrating for you. If I were in your situation, I would definitely feel the same way.

We do want that your experience with iTunes to be pleasant, however, I regret to inform you that your request has been denied. In accordance with the iTunes Store Terms of Sale that you agreed to when you created your iTunes Store account, all sales on the iTunes Store are final. This policy matches Apple’s refund policies and provides protection for copyrighted materials.

Please review the iTunes Store Terms of Sale for more information:
http://www.apple.com/legal/itunes/ww

As mentioned earlier, the iTunes Store is not responsible for the loss of purchases and encourages customers to back up their hard disks regularly. If an item needs to be replaced, you can restore your purchases from the backup and avoid the need to purchase replacement copies of titles from your collection.

Additionally, please make back up copies of your new purchases on a regular basis.

Apple’s recommendation then is that you keep a backup of your purchases! This contradicts The Mac App Store’s advertised capability of facilitating the re-download of apps you already own.

To conclude their email Apple went on to firmly slam the door in my face:

Again, I apologize for any inconvenience you have experienced. Any additional emails from you regarding this issue will not receive a response from iTunes Store Customer Support. Thank you for understanding.

That was not the response I was expecting from Apple’s renowned customer service.

What value are Apple adding to justify taking 30% of the sale price? Not much in my opinion. They aren’t future-proofing your purchases and in my experience their customer support isn’t great either. If you’re given the choice, my advice is to purchase apps direct from the developer instead.