Let’s be clear about this: Linux isn’t dividing into paid and unpaid. It’s not going the freemium route (although the cynical will suggest that Canonical might be thinking about it). What we’re seeing, though, is the development of a clear split. A kind of meiosis.
Debian 7, Fedora, and openSUSE are one head of the hydra;
Mint, Zorin, and Ubuntu the other.