So here's a question:

What (if any) are people's strategy to keep their demos downloading and their games selling for the long run, i.e. several years - which is the time-span over which the true success of a shareware game finally becomes apparant?

In the past I've primarily done this by updating a demo from time to time, hence getting new downloads as the demo moves to the top position - but I'm sure there must be other/better ways as well.

Intensity XS ReCharge was selling pretty reasonably for a few months, then sales started dropping off. Wonderland has just been released and is selling ok so far, but again I'm looking forward to things I can do now that might help its "long term survival". :)

Any ideas?

I think Steve suggests releasing expansion packs, and stuff like that. That gives incentive to current customers who already have it to buy the expansion, and it shows new customers that the game is good. Since "who would make an expansion for a bad game." :)

Here's the relevant article http://www.dexterity.com/articles/get-more-sales.htm