Last summer I decided to write a book called “The Gross,” subtitled, “The Hits, the Flops, the Summer That Ate Hollywood,” and hence bought myself a front-row seat for the opening of every major motion picture scheduled for release during those make-or-break months. That “seat” wasn’t actually situated at the multiplexes; rather I effectively sat next to those filmmakers, distributors and others responsible for the movies of summer on those fateful Friday nights and Saturday mornings when the data rolled in and the hard decisions were made about ads, bookings and overall strategy.

The purpose of “The Gross” was to determine why these particular movies got made and how they performed in the marketplace. And the deeper I dug, the more I realized both the truth and falsehood of that oft-quoted William Goldman comment , “In the movie business nobody knows anything.” In point of fact, I discovered that everyone knew everything — indeed, almost too much.

The key players were awash in data on overall audience awareness plus the reactions of various demographic groups to the campaign, subject matter, even the ending, and every other imaginable iteration that research could conjure up. I have never seen so many executives swimming in so many statistics.

There was one question that defied analysis, however. Would anyone actually pay to see the movie? Even more important, in the case of two of the most expensive films, would the audience pay to see two movies with essentially the same story line, “Deep Impact” and “Armageddon?”

After its initial test screening, “Deep Impact” was the movie that didn’t seem to work, but some re-editing and reshooting changed all that. It emerged a big hit. The first responses to “There’s Something About Mary” suggested that filmgoers were reacting favorably, but no one seriously predicted it would become a global blockbuster. It eventually would actually rise to the top of the B.O. list after seven weeks amid the also rans.

In the same vein, tracking studies revealed a tremendous awareness of “Godzilla,” but no one was able to forecast that, when the movie failed to deliver on all cylinders, the very hype that created that awareness also would trigger a curiously antagonistic counter-reaction.

When “Armageddon” was hit by a fusillade of critical reviews, the marketing executives at Disney quietly but insistently reminded the media that movies of this sort were effectively critic-proof. Their tests indicated that audiences liked the movie a lot better than the critics, and $ 500 million later, they had the last laugh.

On the other hand, the absolutely ferocious one-man media campaign launched by the normally reticent Warren Beatty in support of “Bulworth” seemed certain to stir up box office reaction. It didn’t. Beatty threw a great party but no one came.

What did it all add up to? Simply that the science of marketing has reached a brilliant state of sophistication — when it comes to toothpaste, soft drinks and hamburgers, that is.

When it comes to pop culture, however — what the lawyers like to call “intellectual product” — an aura of mystery stubbornly remains in place. The ad men may mount multimedia fusillades to build global awareness, but they cannot guarantee that audiences, once aware, will respond to the message.

Some movies insinuate their way into the zeitgeist — or “zitgeist,” as Daily Variety describes the teenage market — while others fail utterly to strike a chord, and, in the end, no one can really explain why. That great “buzz” seems to emanate from a weird amalgam of word-of-mouth, newspapers and magazines, and from the dark recesses of cyberspace. And while suddenly one movie becomes a megahit, others, with “hotter” casts and subject matter, fall pitifully by the wayside.

That’s why, in the end, nobody knows anything, yet everybody knows too much. And that’s also why there will be plenty more summers that “ate Hollywood.”