This is really big news on the Office Store front, at least in my humble opinion, and straight from the Office News blog: http://blogs.office.com/b/office-news/archive/2013/10/01/office-store-investments-bring-new-opportunities-to-developers.aspx.
It reads as though we'll be able to submitting updates to existing apps and submitting new apps for approval which leverage a subscription model sometime this month (October 2013). These apps will be available for purchase in the store starting in November! Looks like some of the supporting pricing model documentation has been updated too.
Now, I am personally a bit less concerned with Apps for Office and more concerned about Apps for SharePoint - naturally - but this is a big deal for both! What is the significance of the addition of this subscription pricing model? The answer is two-fold for me:
1) Constant revenue stream
This is a big problem I have had with the whole movement toward apps in general. For phones, tablets, you name it - anything you buy apps for. I know Apple addressed it a while ago - which was great - but for those of us taking a hard look at SharePoint 2013 app feasibility - how do you build a business focused app, sell it for a one-time fee, and support it forever? It's not exactly a business model I'd be to ecstatic to jump into.
There was the option of making the app free and building your own subscription model into it, but knowing sometime down the road that Microsoft was going to release this functionality to the store didn't really drive me to dedicate resources to building one of my own.
2) Support / maintenance costs
This really goes hand-in-hand with the requirement of a constant revenue stream, but I like to highlight it due to the importance of it in planning an app. Typically a solid app is going to require some kind of back-end system or infrastructure as well as people to support it. I know there are apps or services out there, such as some of the platform agnostic messaging apps, which are reliant on outside capital to support their infrastructure and development while the business grows. There is nothing wrong with the outside capital approach and it could very well be used to when developing subscription apps - but the subscription model provides that clear revenue path to support and maintain what is required for the app to function. It also makes the business model a bit more desirable if you do need capital.
Take a document conversion app for SharePoint Online as an example, the conversion itself needs to happen somewhere outside of SharePoint and someone needs to pay for that processing power. A subscription takes care of these costs. Don't get me wrong, a large enough single purchase price could as well, but a small monthly cost is easier to sell than a large one-time cost.
There are many more reasons why this announcement is important to app developers and businesses, I for one am just happy the Office app subscription model is becoming a reality!