The association of shareware professionals, which I joined for a year, has a few examples of success. Winzip apparently made lots of money, and its creator could earn a living off it it. A few others worked well too.
Apparently, software utilities are a bad category for shareware, and they don't do well at all. I think games would work better, because my wife has bought several flash games online. But to create games, you have to use Adobe Flash creator, and it costs $699 to download. That's pretty hard to justify.
It is also possible that Hotkey Jumpstart doesn't even work for most computers. It has when I tested it, but if it weren't working at all, I doubt that anybody would bother to email. Having a shareware product makes beta testing difficult.
So shareware hasn't worked for me. I think it would work better in these areas:
I got an email from the marketing director of a company called Onflow. Onflow was trying to compete with Macromedia Flash. Their product was better because it allowed smaller downloads. If they could get their browser plugin installed on a lot of browsers, then they could (like Adobe today) charge advertisers hundreds of dollars for their program to create ads. According to this marketing guy, if I included the Onflow installer with Banshee Screamer Alarm, they would pay me 14 cents a download. I accepted, and I included their installer in my program.
A few months later, I got a check for about $1014 US, which I used to buy much needed clothing (my wardrobe at the time consisted of T-shirts that I got by signing up for things online). Then the checks stopped coming. Apparently Onflow went defunct in the tech crash.
So at one time adware was a very successful model. But what about today? I recently researched this topic. We all remember when the Opera browser had banner ads. At one point, pkzip for windows had banner ads too. I searched for ways of including ads in my programs, but all the companies that do this have apparently gone out of business.
The most successful company is Zango Cash, which apparently pays a huge rate for installs (if their web site is true). I refused to work with them, however. After some research, I found that they are the creators of the CoolWebSearch toolbar, which crippled my grandmother's computer. I spent a couple of hours trying to remove it, so I will not inflict this on people even for .40 cents a download.
My main problem was that people didn't have to visit my web site in order to download PhotoWipe. So I modified the installer to open up a "thank-you for downloading PhotoWipe" web page after you install it. (This is also how I track how many downloads vs installs I have).
On that web page, I put in the google ad for Picassa, which is actually very relevant. It says "Organize your Photos with Google Picassa". So problem solved! Every install gets exposure to the ad. One important remark: Google claims their "referral" program pays "up to" $2 per install. This is a blatant lie. Actually, I get 10-20 cents per install.
One problem was that (as far as I can tell) google referral ads don't change their language according to the user, but most of my installs were coming from Japan and Spain. My php code takes care of that, my choosing the ad based on the HTTP_ACCEPT_LANGUAGE code.
Once a week or so, somebody clicks on a $1 ad and my profits skyrocket for that day. Also, I seem to get a few dollars more, for a couple of days, whenever PhotoWipe makes it to the front page of a major web site (usually in Japan). But such earnings are short-lived, and the bandwidth costs make up the difference.
The "Thank-you for installing PhotoWipe" page also has a paypal "donate" button, as does the Help menu. In one month, I have had three donations that total to $18. At 15,000 installs (that's installs, not downloads), that's pretty dismal.