How does an adware generate revenue for its creator?

Q. How does an adware generate revenue for its creator?

Answer: -

An Adware is a malware that is created to generate revenue for its developer. An adware displays online advertisements using pop-ups, web pages, or installation screens. Once an adware has infected a substantial number of computer systems, it generates revenue either by displaying advertisements or using “pay per click” mechanism to charge its clients against the number of clicks on their displayed ads. Adware is usually annoying, but harmless. However, it often paves way for other malware by displaying unsafe links as advertisements.