OK, but what do you "need"? What brands do you buy? How did you decide those were the brands you like and would continue to buy? Even stuff like shoes, clothes, household goods and food, etc. Ads aren't just there to convince you to buy things you don't need, they're to prod you in the direction of a brand.
I guess if you buy all no-name brand stuff at the grocery store, get no name clothes or shop at a second hand store, and never participate in larger consumer culture, one could say that they are not influenced by ads, but that would be about 6 people in North America.
I shop at local farmer's markets all the time. I've gone to the same one pretty much for about 5 years. A new one opened that played a radio ad constantly during the work day, advertised their products and location. I checked it out and I liked it. I'll still go to the other place, but I will definitely return to the new one. Advertising in action!