Communities and feedback are all fine and well, but at the end of the day, I suspect that sales of the "standard" version are needed to cover the expense of supporting a "free" version.
IMHO, the free, or so-called "hobby", version of Sitefinity is quite simply too feature-rich for its own good, and in my experience, most SMBs will happily do without versioning, flow-control, and the few other differences, leaving little incentive for them to "upgrade" at any point.
I've built a number of sites for SMBs, based on the approach of using the "community" version to get a foot-hold, and upgrading them to the "standard" version once they are comfortable with the product... and to date, not one of them has felt the need or desire to pay for the upgrade... they are all perfectly happy to continue using the free version.
It would perhaps be a different matter if there were more significant limitations on the free version, like no support for compiled dlls as controls, or no support for custom modules, or some other compelling reasons for SMB users to upgrade, but as it stands, the free version is absolutely good enough to support commercial sites for an awful lot of SMB installations.
Personally, I think that a quality product, with good documentation and support, at a fair price, will flourish in this market, that is full of half-baked and poorly supported products, particularly if there is a price/feature matrix that provides solid reasons for people to upgrade between versions.
I can still see a place for a free, or "Express", version in such a marketing plan, but only if it were significantly stripped down so that SMBs would not be so comfortable using it to run a commercial site.