When people type “Internet phenomenon,” it’s usually that hilarious thing you get in your email inbox from an co-worker or friend with a “OMG SOOO FUNNY!!!” subject line.

You click on the link: selleckwaterfallsandwich.tumblr.com. The page loads, and it’s simply a series of kitschy photo-shopped images placing actor Tom Selleck — yup, that mustached Magnum PI of Hawaiian aloha shirt fame — in different scenic waterfalls with a rotating menu of Higgins-like sidekicks: Salami, pastrami, bologna, cheese steak.

Since January, the simple photo mash-ups of this Tumblr-hosted single-topic blog have been shared (and even imitated) widely, and it’s considered the latest “LOLCats”-like meme (you know, those cute photos of cats with funny but often grammatically-incorrect “iz mah house!”-type captions).

AV Club appropriately blogged about Selleck Waterfall Sandwich with the apt title “Great Job, Internet!” The blog itself is the brainchild of Greg Szmurlo, a California-based copywriter who cracked to ABCNews.com that the idea came from a dream where, “Tom Selleck’s mustache spoke to me in Portuguese and told me to ‘make this dream a reality.’”

In a Gchat interview, Szmurlo admits that the irreverent site sprang from the “non-filtered creative side” of his work with David&Goliath, an Los Angeles creative agency that “helps challenger brands fight their way to market leadership.”

“Well, I am the type of guy who will come up with a lot of ideas,” he explains. “(So) I made it a goal of mine to stop just writing them down and start doing some of them.”

For a professional who has been involved with campaigns for companies like Kia and the Monte Carlo casino complex, Szmurlo is positively Don Draper-like on his creation: Mum on the details (he dares not pick a number one sandwich, since it’s like “choosing favourites among your children”), and on where it’ll go (he promises a soon-ish ending capped with a farewell posting).

But then there’s the official Threadless Selleck Waterfall Sandwich T-shirt, and the awareness that what passes for offline “time waster”-tagged office humour could also be a new medium for word-of-mouth integrated brand campaigns. (Imagine if Whiskas claimed responsiblity for LOLCats?)

“There is definitely a rethink of what works and doesn’t going on in the advertising realm,” Szmurlo says, citing the recently sponsored Absolut Vodka free web film “I’m Here” by celebrated director Spike Jonze as an example.

“Unfortunately, too many agencies are still doing what doesn’t work... I think it will take awhile to get there.”

Imagine! Silly word-of-mouth memes as the future crowd-sourced brand campaign.

But if you blink and just miss it, don't worry: It’s still just a silly time-wasting Internet phenomenon.