From Fedora Project Wiki

Ecosystem Through Extras

Clue -- this is what IBM, Intel, Dell, Hitachi, and others have bought with their labs and development staffs. Think, "OSDL for me."

Through EPEL, a customer or ISV/IHV can push out or support (co-maintain) a Fedora Extras package. The package gets 6 to 18 months additional testing and adoption in the community; it is prepared to be built for future enterprise versions; and can be supported easily by the customer or vendor for the entire lifespan of the RHEL release.

There is an economy of scale at work here. You have to commit a little of someone's time. The work can be done by any semi-competent system administration team, who are packaging work from a FLOSS project. This team channels bug reports and the like from your company, keeping the quality clean, pure, and sensible. Keeps you from having to turn the entire company into FLOSS users (and bugzilla reporters, etc.) Result is this package that continues to receive huge integration testing, adoption, etc.

You might open source a library, that your closed source application makes calls against. You gain on the library in the community, gain build and testing through EPEL, and ensure that your closed application is more solid.