There's no doubt about it: if you have marketing that is fresh and attention-grabbing, you'll sell boatloads of your product.
But, why?
Who among us will admit that an obnoxious commercial or a publicized controversy would actually persuade us to buy a product that we otherwise wouldn't? Maybe not you or I, but clearly there is a huge consumer base that operates in just this way.
That's why repetitive and ridiculous commercials flourish: because they're effective. Owners of discount furniture chains tend to be the most egregious offenders in the marketing world. Their commercials are horrible, but they help to raise the profile of that particular business, thereby bringing in more customers and financing more ridiculous commercials.
The media attempts to guess what it is that we want, and we in turn want it. It's a strange sequence of events, but such is the nature of our society.