The answer to the mystery is that advertising is far more about name recognition than trying to sell something specific. Why are there so many commercials for Coca Cola when everybody already knows about it? It's BECAUSE of all those ads that everybody knows about Coca Cola.

For better or worse, you are more likely to buy something from a company you've seen ads for. Is it logical? No, not really. But advertising isn't about the application of logic. It's about the application of human behavior.