If all goes well, I see Personable as being a hosted API provider for those who don't want to bother with hosting it themselves, with the source code otherwise

If all goes well, I see Personable as being a hosted API provider for those who don't want to bother with hosting it themselves, with the source code otherwise available for those who don't mind, or don't want to relinquish control -- similar to how Wordpress operates currently. There's no inherent reason you can't profit from an open source service, especially if you're able to provide value to those willing to pay for the convenience of not having to run the service themselves, and/or those unable to. Good luck either way. Closed source may not be the death knell you expect.