> In a new US marketing effort, Microsoft is offering developers $100 per app for newly published applications submitted to the Windows Phone Store or the Windows Store by June 30th. Developers can net $2,000 in total by submitting up to 10 apps to each store.
https://www.theverge.com/2013/3/19/4124548/microsoft-paying-...
I expect some of its current shovelware still dates back to those efforts.