>An ad is never helpful because ads are designed to mislead me into buying something I didn't need or knew about before I saw the ad.

Ads can sometimes be helpful because they make me aware of products or services that can improve my life. A lot of us want to make life easier/better but we realistically can't have all possible knowledge about science or inventions that can help us.

For example, I learned about linters (PC-lint) to analyze C code from C/C++ programming magazines. At the time (1980s), I wasn't aware such software existed. The ads helped me learn about C errors and I bought the program and using it improved my skills. Code linters are open source and free these days but back then, a quality C linter cost money. (http://www.polyweb.com/blog/index.php/archives/9)

Another example... when I bought a new truck, I started accidentally damaging the paint on the truck bed by sliding things in and out and worrying about rust. I thought I had to get a rubber mat to protect it. But then I saw an ad for a spray on truck bed liner. That was the superior solution and one of the best smartest purchases of my life. I can throw anything in the truck bed without a second thought and the coating has still held up for 20+ years.

People out in the world are constantly inventing "better mousetraps" that make my life better and I like to learn about them.

That said, 99% of ads are worthless such as ... Google search ads, Youtube ads, podcast sponsorship ad spots, and all the "brand awareness" aspirational ads on tv that prey on your insecurities like perfume, beer, Nike "just do it", etc.