People are either going to buy LFS or they're not. The only other variable factor in there is time. Some people take longer to come to a financial decision, and others really WILL wait for S2 to be Beta'd and released before investing. That's a mind-set that holds true to me, for everything else other than LFS. Why it broke with me for LFS I'm not sure. Community, I think.
Every aspect of the LFS landscape seems to have been carefully reasoned and plotted out by the Devs. It's not something I have to worry about, fortunately. At the end of the day, I wholly believe the Devs have made the demo what it is because they've figured out what works.. the ratio of demo : licenced drivers at the end of the day is going to be managed by the Devs simply because they have the ability to mathematically calculate their income : outgo in relation to demo : licence.. something we can't do for them.
I like the demo as it is, tbh. I think the content is just right. It's generous, with 3 cars and 4 track configurations (rev and rally), and the fact that there's no time limit means that communities have time to build. If it takes 2 years for someone to realise they want to be part of an even bigger community, who does it hurt in the meantime? And if they continue to play demo, create teams, race competitively and nicely, and never decide to join the "big boys", they are at least advocates of LFS and ultimately will cause others to be inspired to buy a licence. Even people who never, financially, directly invest in LFS can do so ten-fold, indirectly.