Hi, I recently released a shareware app and I thought I'd share my experiences so far, since I didn't see too many pages that gave concrete numbers for something similar.
The app is Pandali Folder Master, and it's an add-in for Microsoft Outlook to make it easier to move multiple folders. It's a 30-day-free-trial download and after 30 days a registration screen will appear and most of the app becomes disabled. (For an interesting discussion of crippling vs not, you might want to check out http://hackvan.com/pub/stig/articles/why-do-people-register-shareware.html – the most interesting thing for me is the guy claims to have made $34K in a year for about two days of work)!
The app was first released mid-July 2010. While there haven't been a huge number of downloads, I think it's enough to start seeing some interesting trends.
1) Slow start to registrations – The first interesting point is that there were no registrations at all for the first three months. Obviously for the first month, everyone was within the 30-day free trial period, so that wasn't too surprising. But for the next couple months there were still no registrations at all, and in fact almost nobody was seeing the registration screen. I was getting depressed.
2) Gradual pickup – The first registrations started coming in mid-October. Around then it was looking like the ratio of registrations to downloads might be about 1 in 200, which was a little discouraging. But then in November registrations started picking up some more, and now the ratio seems like it is more like 1 in 50, possibly even better.
My theory is that this is the sort of app that people might use once every few months but not every day. And so it took a while for the first downloaders to use the app again. Downloads have increased over time, but not as dramatically as the increase in registrations in November. Downloads currently may be about 2x what they were intially.
Another interesting item is with Google AdWords. I experimented with Google AdWords and Microsoft's adCenter. I'm still an adwords novice, but after a couple of weeks experimentation and maybe a hundred clicks or so, incredibly I could not track a single download to AdWords or the bing equivalent. That doesn't mean there weren't any as not everybody's referrer was set, but still very surprising, especially compared with the ratio of downloads / click via some random forum posts I made. A significant number of these clicks came from the Google "Display Network" (sites using AdSense and other non-search sites) before I turned that off – part of me is suspicious if there is some heavy click-frauding going on with the Display Network sites.
Anyway, the app has brought in nowhere near the $34K that the other guy made with his two days of work, but we'll see what the future holds. These experiences are of course particular to this particular product and so you may achieve very different results with a different product. If you've released a shareware app or a mobile app, or even a freemium website, I'd love to hear your experiences. Thanks!