Explained: What do Top, Free and New Apps mean in the WP Marketplace?

Microsoft is finally telling us what goes into the various sorting calculations in Marketplace (which always seemed to be a bit of an enigma, particularly ‘top’). Well here’s the answer:

Top
Top is a filter used to return a ranked list of paid apps, sorted by downloads from the previous month. The algorithm used to determine sort rank gives greater priority to recent downloads, so an application with 1,000 downloads yesterday will be ranked higher than an application with 1,000 downloads three weeks ago.
Free
Free is a filter used to return a ranked list of free apps, sorted by downloads from the previous month. Like Top, recent downloads are weighted heavier than those that occurred a few weeks prior.
New
New is a filter used to return a list of the newest and/or most recently updated apps. The ranked order for New is determined by the most recent published apps during the last catalog refresh which occurs, on average, a few times per day. Because they have so few downloads, newly published apps typically rank low on the Top and Free lists. The New option helps prevent them from being overlooked and appeals to customers interested in the latest releases.
Featured
Featured is a list of apps selected by a group of human curators on the Marketplace team (Yes, there are people who play with apps for a living). We’ll look more closely at what these people do and how apps get featured in a future series installment.

They also go into insight about what gets an app to be top rated.

Likelihood of Windows Phone features and attributes being present in Top 50 apps compared with all other apps

Toast Notifications
4.1 times higher

Trial API
3.8 times higher

Live Tile mention
3.7 times higher

Push Notifications
3.2 times higher

Location Features
1.6 times higher

Days since most recent update
94.7 days newer

There’s some other really interesting data but hopefully devs are reading this and pushing there apps to where consumers to what consumers are demanding.