Apple's App Store had the top score among mobile application storefronts ranked by ABI Research, but Microsoft's Windows Store narrowly beat the field for its degree of innovation.
The rankings point to a central issue with application storefronts: Size, which ABI calls "implementation," compared to "innovations" in an app storefront. Microsoft looks at more criteria in recommending apps than other stores, ABI said Wednesday.
When both implement and innovation scores are combined, Apple wins with a ranking of 80.8 out of 100, compared to Google's 72.2 and Microsoft's 63.9, according to ABI researcher Aapo Markkanen in an email interview.
In terms of implementation, ABI considers revenues earned by an app store, market share and the total inventory of apps maintained with a "reasonably strict quality control," ABI said.
ABI didn't share its findings on all those measures, although Apple's App Store had more than 700,000 apps late in 2012, nearly matched by the Google Play store. Microsoft recently announced that it had added 75,000 apps to its Windows Phone store in 2012, putting the total at more than 125,000.
Market research firms IHS iSuppli and App Annie said last year that the App Store was expected to earn $4.9 billion in revenue for 2012, four times the revenues of Google Play.Windows Store is expected to trail both by a distant margin, analysts said.
Even so, ABI found that Microsoft narrowly beat top-ranked Apple on the innovation criteria, mainly because of the Windows Phone store's "fresh approach to app discovery, as well as Windows Phone store's overall solid usability."
On the innovation scores, ABI scored Microsoft at 77 out of 100, compared with Apple's score of 76. (ABI did not release similar scores for Google and others.) Markkanen said innovation includes five criteria -- discovery, quality control, ease of use, breadth of ecosystem (including availability of music, video and other content and smartphone and tablet apps) and hosting and deployment (including file-size limits, and download methods).
Notably, Markkanen said Microsoft scored well for discovery for ease of use. He called the way that Microsoft ranks top apps as "more holistic and transparent" than other app stores.
"Microsoft does seem to invest strongly in both personalized recommendation and editorial curation of apps," Markkanen added. He noted that Microsoft has publicly stated its ranking of apps takes into account how many times an app is pinned to a user's home screen, how often it crashes and how often it is uninstalled.
With such practices, Microsoft can show how "quality apps with modest and loyal user bases are favored over apps that generate tons of downloads but are failing to retain the customers," Markkanen added.
As a result, Microsoft's approach "should favor developers with good products and little extra money to spare, over the ones that have mediocre products but big marketing budgets."
Still Markkanen was realistic, noting that all the success in the world for the Windows Phone store "won't really matter if the devices powered by Windows Phone end up selling badly."