Apple spends almost nothing compared to Samsung's giant advertising dollars anyways. They don't need to, really - Apple's solid reputation lets the media do their ads for them.

Just like how Apple doesn't need to buy billboards at the mall when they have bright, inviting stores of their product to entice you.

Also, why wait until you've announced a major media event before buying advertising to coincide with said media event?

In other words, if Samsung is buying advertising to crowd out competitors' ads on the day of an Apple product launch, Apple is surely not the competitor they're hoping to crowd out.

...to stop your competitor getting it?