An interesting anecdote...when I was in middle school, an account exec for McDonald's came to speak to our class. He told us that in our local market, McDonald's Corp wasn't convinced that the TV and radio ads were having a significant effect on buying behavior. So for one day, they pulled the ads in that market. They found that sales absolutely plummeted in that day, so they scrambled to reinstate their regular ads and all was well. Of course this is anecdotal evidence, but it made a big impact on my middle-school mind :) Everyone thinks they're not affected by advertising.
