Although advertising is a big part of marketing, it's not really as big as everyone makes it out to be.
I know a lot of people that just buy things because it's what they've had and/or enjoy the most.
I am the same way.
When I go out to get groceries or something, I always go out to eat.
When I go to the store, I always get a Pepsi or Sprite and hot Cheetos.
When I go to McDonald's I always get a southern style chicken sandwich.
When I go to Subway I always get an oven roasted chicken breast foot-long w/ pickles, lettuce, red onions, and American cheese.
If I go into a place and see they have something, I'll buy it if it looks good, but if I see it in a TV ad I have almost know more motivation than before. (Unless it's a video game or movie.)