The title to this post--"Is commercial open source possible?"--is meant as bait, of course. I work for a commercial open-source company and definitely feel that it's possible. Indeed, without "commerce" I don't think open source would be nearly as mature as it has become. Cash fuels code.
But even so, Larry Lessig raises an interesting question on whether commercial and community ever really mix:
It would be very odd if a friend apologized for missing lunch and offered you $50 to make it up. And it would very, very odd if your girlfriend, at the end of a great date, offered you $500 to spend the night. Or if Wal-Mart asked all customers to "pitch in and help Wal-Mart by sweeping at least one aisle each time you shop." Or if McDonalds asked you to "help out" by promising to buy hamburgers at least once a month. Money in the sharing economy is not just inappropriate; it is poisonous. And "helping out" is not just rare in the commercial economy. It is downright weird.
It's a bit of a gross generalization, but there's a kernel of substance to it. I don't think, however, that the conflict is between community and commercial. The conflict arises when a company tries to feed its community and commercial customers from the same bucket of bits.
As I've noted recently, this can create tensions with one's community because it can lead a company to downplay or even downgrade its community-focused product. In many ways, the approach that Zimbra, SugarCRM, and others take (i.e., clearly separate proprietary extensions or add-ons to the community product).
No, community is not inimical to commerce, but there are clearly better ways to mix and mingle the two. The companies that figure this out will be those that dominate the next decade of software. Google has figured it out. So, too, has Red Hat. You?