Customers love the Mac App Store. At least, it seems like many of them do. But as Apples one-stop shop for Mac apps grows older, it becomes increasingly more restrictive to the developers who sell apps there.

In a post on his blog titled The Mac App Stores future of irrelevance, Instapaper developer Marco Arment asked: How many good apps will be pulled from the App Store before Apple cares? He continued: My confidence in the App Store, as a customer, has evaporated, since he can no longer feel certain that an app he buys today will remain available in the store later. Arment argues that the App Store is no longer a reliable place to buy software, at least for him and other Mac App Store customers who buy apps that developers later feel forced to pull from the store. His conclusion: The Mac App Store is in significant danger of becoming an irrelevant, low-traffic flea market where buyers rarely venture for serious purchases.

Arment references the most common Mac App Store concernits sandboxing requirement that can limit what functionality developers may include in their apps. By requiring that developers sandbox their apps, Apple can ensure that apps wont poke around where they dont belong on users Macsbut that limitation can potentially require apps to incur significant changes.

Arments post touched off another round of Mac App Store debates. He believes that because the Mac App Store is bad for app developers, that the overall quality of apps in the store will steadily decrease, which will be bad for developers, customers, and Apple alike.

Beware of the big, bad Mac App Store

The case against the Mac App Store

Of course, the Mac App Stores restrictions come with at least some precedent. All its limitationssandboxing, lack of upgrade pricing, and so onwere part of its older, more popular brother since day one: The iOS App Store. But, Arment says that precisely because its always been that way, there arent huge classes of [iOS] apps that people have grown accustomed to using that are suddenly not available anymore.

The iOS App Stores restrictions work (for the most part), Arment says, because the platform has grown around them. They mostly dont get in the way. But on the Mac, the App Store policies are being retrofitted into a well-established environment that theyre fairly incompatible with.

Theres no arguing that theres a difference between restrictions in place from the get-go (the iOS App Store), and restrictions retro-fitted over time (the Mac App Store). Thats not to say that the Mac App Store launched without any restrictions; from day one, it lacked support for upgrade pricing, limited root access, and banned apps that accessed private APIs (application programming interfacecode provided by Apple that developers can use to make their apps) or attempted to tweak elements of the Macs interface.

And Arment isnt the only developer who thinks the Mac App Store is, at least in some respects, doomed. The Mac App Store faces a risk of becoming irrelevant, or at the least, far less than dominant, because of Apples failures, Paul Kafasis of Rogue Amoeba said. Many apps, Kafasis says, including our own, have never entered the store due to the onerous restrictions in place from day one. Airfoil and Audio Hijack Pro are both enormously popular applications which would need to have major features removed in order to fit within the App Store. Castrating our apps is simply not appealing.

Kafasis recognizes the benefits of the Mac App Store: [It] made it easy for developers to sell software, without a lot of overhead. But, he adds, the obstacles to selling software have been shrinking for years& Selling directly is easier than its ever been. The Mac App Store is a nice enough idea now, but it would have been truly revolutionary 20 years ago.

Customers will go where the software is, Kafasis continued, and if the software is only available outside the store, most customers will still find it. And indeed, they did just that for decades before the Mac App Store ever existed.

In fact, Kafasis argues, its possible the store is educating folks as to the existence of third-party software, period, and once new potential customers are aware of that fact, it becomes easier to sell to them anywhere. That may become increasingly important for Rogue Amoeba: Kafasis says the company is working to sandbox Piezo, but that doing so may be impossible. If were unable to do that, well have little choice but to shift Piezo from the Mac App Store to direct sales exclusively.

And as it does for Arment, that sort of uncertainty turns Kafasis off as a customer: For me, when I see an app is only available in the Mac App Store, Im actually less likely to be interested. Will it still be there in 6 months or a year? Will Apple force it to remove functionality? That uncertainty makes me desire a direct version, every time.

In defense of the Mac App Store

One common response to Arments arguments is that they really apply only to geeks and power usershardcore Mac users who run powerful software most likely to get bitten by App Store restrictions. In a followup post, Arment countered with his belief that the Mac App Store problems he describes arent limited to such users. Because geeks are evangelists and thought leaders, Arment suggests, their influence reaches many typical Mac users too, and those users will feel similarly put-off by Mac App Store apps that get forced out of the store.

But not all developers see the Mac App Store situation as negatively as Arment and Kafasis.

James Thomson from TLA Systems sells apps in both the Mac and iOS App Stores. And in important ways, the Mac App Store continues to work out great for him: Weve had PCalc in the Mac App Store since it opened, and weve seen noticeably higher sales from the App Store than through other channels. So, from a visibility and ease of purchase point of view, it would seem that [the Mac App Store is] a success.

That said, Thomson does have concerns. He said that TLA is in the process of submitting our first update with sandboxing switched on, and weve had to remove an (admittedly, very minor) feature to do so. Its not ideal, but we dont really have much of a choice if we want to sell in the store, he says.

But Thomson doesnt necessarily agree with Arments suggestion that more customers will increasingly shop for apps elsewhere: Even though you can see a lot of folk talking about it within our small sphere, I dont think were the average consumer by any means. Most people will just buy through the store because they are used to the experience from iOS, and its right there in front of them.

Rather than expecting more customers to abandon the Mac App Store, Thomson predicts the opposite: A small, and shrinking, number will buy specialist software directly.

What it all means for Mac users

If Arment and Kafasis are right, and the Mac App Store is destined for inconsequentiality, thats a clear problem for Apple. While Arment was quick to clarify that he never intended to suggest that users would completely abandon the Mac App Store, he added that such abandonment isnt the only way that the store could suffer: The problem is that itll be relegated mostly to simple, cheap, often subpar apps, and for the few good apps that remain, users will mistrust the Mac App Store as a stable place to buy them and expect future upgrades. The result? In Arments view, without significant changes, the Mac App Store will just never become good enough that Apple could require that Macs only run App Store software.

Is that hypothetical Mac App Store-only OS Apples panacea for the Mac? iOS, of course, famously supports only running third-party apps purchased from its App Store. Does Apple hope to one day make Macs run the same way?

Mountain Lions new Gatekeeper feature lets users limit which apps can run on their Macs; the default option limits Macs to running Mac App Store apps and apps from identified developersdevelopers whove registered (for free) with Apple, but whose apps arent subject to Mac App Store restrictions. Could a more restrictive, Mac App Store setting become the new defaultor perhaps, the only option?

Arments guess: I dont think it will happen for a while, but I do think that [restricting Macs to Mac App Store apps is] Apples eventual goal. And if it does happen, no matter how far in the future that is, I bet well all scream that its too soon.

Thomsons take: Yes, I can completely see Apple locking things down more in future. But, I would expect them to first completely remove the ability to run non-signed code, and I dont think too many people would complain about that. Were a good couple of years away from only allowing App Store apps Id sayprobably not in 10.9, but after that it wouldnt surprise me.

And Kafasiss perspective: I think that would be disaster for everyone. It would be bad for developers who dont fit into the Mac App Store, certainly, and thats a growing number. It would be bad for users, who would no longer have access to a wide range of very useful products which simply dont fit within the Mac App Store. Ultimately, I believe it would be very bad for Apple as well, as their now-thriving Mac platform would be damaged.

What Mac users should do

Perhaps, at this point, youre wondering what you should do. The first step is concluding how you feel about the Mac App Store and Apples increasingly strict rules regarding the apps that can be sold there. If you dont mind them, keep contentedly shopping in the store.

But take pause. When we talk about the importance of backing up, we often say that its a question of when, not if, your hard drive will fail. With the Mac App Store, its nearing certainty that if you havent yet been stymied by the impact of one of Apples Mac App Store rules, you will be soon.

That stymieing might take one of several forms: A developer of an app you love might release a brand new version with a brand new price tag, since theres no option to offer upgrade pricing. An app you love may be forced to strip out features you depend upon to comply with Apples rules. Or developers behind an app you love may find that they simply cant keep the app in the Mac App Store anymore, and pull it (see Postbox, Alfred, TextExpander, and Moom, each of which has been forced to move out of the App Store and return to a direct sales only model). Whether youll be able to cross-grade from your Mac App Store version of that app to a standalone, external version will be at the whim (and maybe even technical expertise) of the developer in question.

While the Mac App Store remains a fine place to buy certain software titles today, the issues are real, and Apple thus far has displayed its characteristic determination to stick to its current plan. If youre concerned, you have two tools you can use: The first is to stop shopping at the Mac App Store when possible, and buy apps direct from developers instead. And the second is to share your feedback with Apple directly.

Its definitely too soon to panic about the future of the Mac App Store and OS X. But its not too soon to be concerned.