They did that. TheVerge reported them paying up to $100,000 to companies to port their apps to the store. https://www.theverge.com/2013/6/15/4433082/microsoft

They did that. TheVerge reported them paying up to $100,000 to companies to port their apps to the store. https://www.theverge.com/2013/6/15/4433082/microsoft-paying-companies-100k-windows-phone-apps https://www.theverge.com/2013/6/15/4433082/microsoft-paying-... That was back in 2013. Foursquare was one of those - MS covered the cost of porting it to WP. They even hired an outside developer team to do it.