system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do people make viruses that just puts pop-ups on your computer?
gpt
Some pages get money by showing ads. The problem here is, ads often only pay for unique visitors. Now if you get to visit such a page, you are a unique visitor and the page gets revenue. So by placing a virus or worm or something else on your pc that redirects you to any page, that contains ads, they scam the people that are paying for the ad to be displayed. Others want to sell funny stuff to you like drugs. The other posters gave valid reasons too.