Adware is software integrated into or bundled with a program. It is usually seen by the programmer as a way to recover programming development costs, and in some cases it may allow the program to be provided to the user free of charge or at a reduced price. The advertising income may allow or motivate the programmer to continue to write, maintain and upgrade the software product.
Some adware is also shareware, and so the word may be used as term of distinction to differentiate between types of shareware software. What differentiates adware from other shareware is that it is primarily advertising-supported. Users may also be given the option to pay for a “registered” or “licensed” copy to do away with the advertisements.
There are concerns about adware because it often takes the form of spyware, in which information about the user’s activity is tracked, reported, and often re-sold, often without the knowledge or consent of the user. Of even greater concern is malware, which may interfere with the function of other software applications, in order to force users to visit a particular web site.
It is not uncommon for people to confuse “adware” with “spyware” and “malware”, especially since these concepts overlap. For example, if one user installs “adware” on a computer, and consents to a tracking feature, the “adware” becomes “spyware” when another user visits that computer, and interacts with and is tracked by the “adware” without their consent.
Spyware has prompted an outcry from computer security and privacy advocates, including the Electronic Privacy Information Center . Often, spyware applications send the user’s browsing habits to an adserving company, which then targets adverts at the user based on their interests. Kazaa and eXeem are popular programs which incorporate software of this type.
A number of software applications are available to help computer users search for and modify adware programs to block the presentation of advertisements and to remove spyware modules. To avoid a backlash, as with the advertising industry in general, creators of adware must balance their attempts to generate revenue with users’ desire to be left alone.