Most often than not, it's adware explicitly included in the installer by the software's creator to make a profit on shareware or freeware. They usually have op

Most often than not, it's adware explicitly included in the installer by the software's creator to make a profit on shareware or freeware. They usually have opt-outs, but the shadier ones do not - and you can legitimately click "next-next-next" and don't read about them and uncheck the button that installs it - that's what they're counting on. If someone like Russinovich didn't see it, it was probably not opt-out. Edit: here's some relevant info http://answers.yahoo.com/question/index?qid=20090518120035AAtbHlN http://answers.yahoo.com/question/index?qid=20090518120035AA... Google purportedly pays U$ 2 per install, I guess Yahoo! does the same