Fishing for rainbow trout? If you're lucky, and you catch one, it'll probably weigh about 2 pounds. If you're extremely skilled and God loves you, you can hook an 8-pounder. You will not catch a 42-pound rainbow trout.

Oh, it's been done. Such mutant rainbows exist, and it conceivable somebody will hook one. But it won't be you. You also won't be struck by a meteor. You won't win the Mega Millions lottery. Though some Japanese guy once did, you won't find a 55-leaf clover.

So don't waste any time or money planning for such events, because that would be stupid. And if you are using somebody else's resources while presuming to outthink the laws of nature and probability, that is practically fraud. Phenomena are phenomenal precisely because they cannot be predicted.

Yet Ad Age and all its competitors routinely hype viral videos as if they were the product of some sort of rarified genius, and as if there were techniques for reproducing the results. What a crock of shiftiness. Indeed, there is an entire industry developing and hundreds of millions of dollars squandered each year premised on an impossibility. Name five branded viral sensations. (My definition: accumulating 10 times as many views as paid for.)

Take your time. I'll wait. According to statistical research by Duncan Watts and others, on average, seeding virals yields 1.1 to 1.4 times the media buy. That's not an insignificant bonus, especially if so-called engaged viewers are more valuable than random impressions, but it ain't a 42-pound trout.

Producing a video with the intention of achieving virality is like going to the racetrack and betting $100,000 on the long shot to win while trotting backward with the jockey juggling barbells. There are wiser investments of client money.

Even in nature, virulence is a weak force. Despite a world containing countless pathogens, epidemics are rare, because the mathematics of contagion work against widespread infection. Virality -- or to use the more correct term, virulence -- needs to have a threshold reproduction rate (Ro > 1) to keep from dying out. The reason we're not all dead is that even the Ebola virus, which is 90% lethal, does not exceed that threshold. So, what? Pepsi -- or whoever -- is going to achieve it?

According to Visible Measures, which is in the social-video business, six out of seven branded videos fail to reach 1 million views, even when "seeded" through paid ad buys.

So, then, is this a broadside against branded content? It is not. Though evidence is accumulating that brandedness suppresses passalong, that doesn't mean brands shouldn't be both creating and curating content for their various constituencies. In fact, as we edge ever further into the Relationship Era, in which trust is the most valuable asset, providing compelling and relevant content through multiple channels is an ever-more important way to sustain connections. For instance, Betty Crocker's cake videos, pure how-to content sought out by moms wishing to bake birthday cakes shaped like dinosaurs and princesses, have been clicked on 70 million times.

And, as I've mentioned before, there is a huge, untapped opportunity for a brand to pass along found video to its various circles, much in the way any friend would.

Finally, brands can be part of larger movements, when those enterprises reside in the common ground shared by the brand and its customers. At the moment, there is an extraordinary experiment going on in South Africa, a Twitter campaign called Close The Tap, aimed at building awareness of preserving fresh water. Built by Native and RSA Web, Capetown and Johannesburg, Close the Tap asks people to tweet a single water-conservation tip. With each tweet, the valve on a (pictured-live) open tap closes slightly. When 10,000 tweets are sent out, the water is shut off altogether. At this writing, it was 40% shut off.

My first thought was: fantastic idea. Why wasn't Pepsi behind it? Or a pharma company dealing in diarrheal disorders caused by bad water? Or Tide or Crest? In the great Venn Diagram of Life, here is where circles intersect. And in those oblong intersections -- not some quixotic tilt at mass contagion -- resides the future of marketing.