[jakobegger]

If your app doesn't actually need support, companies won't buy support. Nobody has ever asked for a support contract for any of my desktop apps.

It's also hard to sell extensions... I've had a couple of people email me with suggestions for paid feature requests, but nobody ever followed up when I made an offer and quoted the actual cost. Maybe I'm just not good at selling, though.

(People do offer to buy group licenses if you add a feature, but that only works for minor features you wanted to add anyway, and doesn't work if your product is free anyway...)