The Internet is saturated with free programs and tools, making promises they fall short of, or that once the software installed performs unwanted acts.
Perhaps you are unaware or this did not happened to you: You are downloading software from an apparently redoubtable maker or distributor of software. You follow the installation instructions and you start using the newly set up software.
In one case, the downloaded browser is a well known and quite popular software. After a while the user had noticed that each time she opened the browser, another two or three windows opened and started pushing games and other crap in an aggressive manner.
She tried to uninstall the unwanted programs, but they simply just popped up again. Finally, after plenty of agony and using various antimalware programs, it seemed that the crappy program disappeared. But only for a while. Soon the unwanted pages opened again. In the end she got rid of the otherwise useful browser, cleaned the computer and now seem to be free of unwanted programs.
This is just a very basic, routine case of installed unwanted programs and many people have had experience with it. - Often people had learned they must be very careful when installing a program, especially if it is a free software.
Does the perpetrator actually makes money by forcing undesirable programs on unsuspecting users? Do people actually give up and purchase the unsolicited crap for good money?
Are there statistics on these activities? Is there promotion in the future for the geek who managed to convince the "Boss" that this and that PUP program will bring in tons of money?
In the developed world the word gets around fast and people see the scam more often and catch on quicker therefore reducing the flow of fast money for the "Brain" behind this kind of scam.
One is not too sure about the situation in the developing countries where many people just now are getting on the Internet and many are just at the beginning of a learning curve in the world of scams and forced advertising of often useless products.
There are many people out there who are vulnerable to the scam involving with PUP programs.
Unfortunately, the scams will continue, and most people will learn only from experience. Like most of us.
