This question seems appropriate for programmers as well as for startups
A few years ago I've developed a program that has a steady group of users. It became quite popular and now we have close to two million downloads on Download.com.
At first I provided the application as freeware to reach as many users as I could, but there is server costs and of course it would be nice to receive a bit of money in return for your effort.
I'm looking for a way to gain reasonable revenue from my freeware application, but still make a bit of money. Here's my experience so far:
Xacti: Low revenue and it took me a lot of emails to eventually get my money.
OpenCandy: Friendly, revenue is ok, good online overview of your downloads.
InstallMonitizer: We're testing with them right now, revenue seems higher and a referral program.
Another option would be to switch to shareware (let's say 30-day trial based), but I think that would cost me a lot of users. The offer screens are harmless in my opinion.
What do you use for your software (opensource, freeware, shareware)?
What are your experiences so far?