This Solitaire game will show you banner ads as well as full-screen video advertisements, making money for Microsoft. But they're not doing this out of the kindness of their hearts.
With Windows 10, Microsoft includes the Microsoft Solitaire Collection app out-of-the-box. No games were included with Windows 8, but you could download the Microsoft Solitaire collection and Microsoft Minesweeper from the Windows Store for free. WIth Windows 8, Microsoft removed the old desktop Solitaire, Minesweeper, Hearts, and other games from Windows. Solitaire and Minesweeper Have Gone 'Free-to-Play'
That helps explain why Candy Crush Saga is automatically installed on new Windows 10 PCs, too. Microsoft has jumped on board the 'free-to-play' bandwagon, which means these games are no longer actually free but have become quite expensive. Microsoft is now making money by nickel-and-diming players with in-app purchases.