Are you unfazed by ads? Annoyed by them? Do you simply "edit them out"? It doesn't matter what the answer is, because they probably work anyway. Advertising doesn't have to be good, it has to rely on the "mere-exposure effect."
Does something have to be good for you to like it? No. It just has to be around for a while. Eventually, you'll come to have positive feelings for it. Don't believe me? Try tracking your response to the next change in fashion. At first it will look like a creative way for people to destroy their looks, but soon you'll see variations that you like, or patterns that you like. You'll learn to create an aesthetic. People don't just get used to anything - they can learn to like it.
The fact that people will eventually begin to find reasons to like anything, as long as they're exposed to it long enough, is called the "mere-exposure effect." It was first tested in the 1960s by psychologist Robert Zajonc. He tried two different experiments - one on animals and one on humans. The animal experiment was fairly simple. He separated a bunch of fertile eggs into two groups. To one group he played one musical tone, and to the other he played another. When the eggs hatched, the chicks in each group gathered around the tone they were most used to.
It's understandable that chicks might crowd near a stimulus they were exposed to when they were developing, but humans don't have an excuse. Zajonc got a group of volunteers and showed them Chinese characters - after making sure they couldn't read the script. After they had been exposed to the characters for a while, they were told that the characters were descriptive words. Zajonc then added the familiar characters to a group of new characters, and asked the students to judge whether the words were describing good things or bad things. Overall, the volunteers believed the characters they were familiar with were good descriptors - like "warm" or "beautiful," - while unfamiliar characters were, in the volunteers' minds, probably reserved for things like "smelly," or "talkative during movies."
Familiarity doesn't breed contempt. Just the opposite. Stick with an object, or person, long enough and you'll find something you'll like about it.
Via Journal of Personality and Social Psychology.