AdAge has released the 2011 list of America's biggest-spending advertisers. Topped by Procter & Gamble (NYSE: PG) as usual in a blowout performance with 53% higher marketing spending than No. 2 AT&T (NYSE: T), the list carries few surprises.

Except this perennial head-scratcher: How can Apple (Nasdaq: AAPL) slide in at a very modest 86th spot, up from No. 100 in 2010?

Let me clarify my bewilderment. TV ads for Apple are few and far between, unlike the marketing blitz that established the iPod and iTunes brands so long ago. Billboards? Also few and far between -- too gauche. There's a smattering of magazine ads, but hardly a massive campaign.

But have you seen a movie lately?

That's where the Apple action is.

For example, Viacom's Paramount gave plenty of product-placement screen time to several paying partners in the current box-office champ, Green Lantern. That includes a duo of Macs for the hero's love interest, prominently placed in an important scene. What makes Green Lantern different is that some characters actually don't use a Mac. I'm told there are Dell (Nasdaq: DELL) and Panasonic (NYSE: PC) computers in the movie as well.

Starting in 2006, Apple adamantly claimed not to pay Hollywood for product-placement opportunities. Yet it's come to this: If major characters use anything other than Apple computers, it's going to be a Sony (NYSE: SNE) Vaio because the movie was produced by Sony Pictures or sister studio Columbia. Go ahead, try it as a drinking game -- it's a very dependable metric.

I'd understand if Walt Disney (NYSE: DIS) threw in the occasional gratuitous Mac plug, since Steve Jobs is the company's largest shareholder. But it's bigger than that, and the Apple allegiance crosses every studio line except, of course, direct computer competitor Sony. Brandcameo says that 30% of the top-grossing movies in 2010 featured Apple products, down from almost 50% in 2009 and market-leading in both cases. I guess that means we had fewer movies with on-screen computers in 2010.

It wasn't always like this, even if you wanted to avoid the Windows trademark. Jurassic Park featured generic Unix computers, and the computers in The Matrix are so vanilla that I can't figure out the brand of Neo's office desktop. But Macs are everywhere now.

So what's going on? Is Apple paying studios big bucks under the table? Are film directors just using Apple stuff as a proxy for the good guys and the cool kids? It's either the greatest cover-up operation in marketing history or the finest free ad program I've ever seen.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.