What are you talking about? It is not even "for free", they get a lot value from the community.
They're nothing without the users, it's not that they would be making it if nobody uses it anyways. Users used to love them, they trusted them, they went on spreading their system, reported issues, created tutorials, flavors, videos, tools, and so on, they helped Cannonical become what it is now.
I don't think they're giving us anything "for free."