^ basically their jobs are to hide links or key words which will drive up websites and google points if they get clicked on. The emails / pm's however are more intriquette, they are a gateway to reading your machine so they can trace what sites you vist, get passwords and drop little "packettes" to track your email and website history. Then they use that info to sites, go in and exploit their crap.

Unfortunately, these also leave you vulnerable to their malicious "adware" that say your machine is infected and there is a registry you can use to clean your computer which again is bogus and if you use it, it ads rep points to the site offering the scan/fix, it can also lead to viruses and again dropped packettes to read your websites etc etc.