The Economy of the Internet
The Rise of Freeconomics and the Threat of Ad-blocking.
You would think giving away products for free at points, might not bring in any business, but you're wrong. The creator of the Gillette disposable razors did this and he made millions. The internet is doing the same. While programs and websites are free, third parties can post their ads by paying the company who owns the program or website. Just because a product or site is "free" doesn't mean money isn't being made for the person running it.
Many people use ad-block so they won't have to sit through the minute or two long ads on YouTube or a site that has your favorite shows that you need to catch up on. Ad-block can be harmful to businesses if you do use it. As stated above, if a website is free, they get their money from the ads showed on that site and if the ads are not allowed to be shown by users, the third-parties don't make money and it could affect the people running the site.