Samsung's advertising is a key piece of its success. In the Android smartphone market there isn't much that separates each phone maker. By going heavy on advertising Samsung took mind share.
This chart only tells part of the story, too. Wireless carriers say Samsung spends a lot on "below the line" marketing like in-store marketing for its phones, as well as paying for training of carrier's salespeople.
Plus, this the U.S. which is only 10% of its overall ad spend, according to analyst Benedict Evans. That means it's spending $4 billion in advertising worldwide.