The Story Behind the Most Successful 'It's Always Sunny in Philadelphia' Promo – Both On Screen and In Real Life

On a Season 5 episode of "It's Always Sunny in Philadelphia," the character Charlie tells the others in the gang that he recently created a product called "Kitten Mittons" in a quest to quiet down the hoards of alleycats around his apartment.

After hearing about a merchandising convention in town, he made a commercial for his product, hoping it would get some investors.

The rest of the group isn't sold on Kitten "Mittons," but they are interested in advertising their bar through promotional products. The rest of the episode deals with their quest to find the ultimate product. They go through things like a real shotgun that can be loaded with liquor, a branded pen, a branded thong, a stress ball that turns out to just be an egg painted green, and eventually a very specific (and graphic) towel.

While the towel served as an in-episode gag, it made the creators real money, which they detailed on their podcast this week.

Now, here's where things get a little more PG-13. In the episode, the character Mac (played by series creator Rob McElhenney) shows Dennis (Glenn Howerton) a towel that he created that, when wrapped around your waist, shows a bottom half of a naked man — front and back — with a couple of different ... sizing options.

On the podcast, McElhenney says he was inspired after a visit from his mothers, where they bought novelty T-shirts of bikini bodies from the Venice Beach boardwalk.

They whipped up a prototype of the "D*ck Towel" and took it to the network, FX.

"We went to FX and said we believe we have a merchandising opportunity," McElhenney said on the podcast. "And they were like, 'Oh, cool, what could we do? T-shirts, like Paddy's T-shirts and Sunny T-shirts?' And we were like, 'Yeah, kind of. But what we really want to do is a towel with two d*cks on it.'"

FX came back and, reasonably, said they couldn't do it, but that they wouldn't stop the guys from selling it if they wanted to.

So, they did. Partnering with the apparel brand Suburban Riot, which you might know for making the "KALE" T-shirt that became all the rage, the d*ck towel became a reality.

The creators also set up a website – d*cktowel.com, which they advertise in the episode as the in-universe website, but it was a real website where fans could immediately buy real versions. It turns out people wanted to do it, because the site crashed immediately after the episode aired on the East Coast.

McElhenney and Howerton had to remind Charlie Day, who plays Charlie Kelly on the show, that the towel idea was, in fact, very lucrative for all of them.

Day: "We didn't make a ton of money."

McElhenney: "Oh yes. We. Did."

Howerton: "We did pretty good."

McElhenney: We made a lot of money from that. A lot of money from that. We sold 50,000 d*ck towels. Fifty-thousand. Within, like, three weeks.

[Warning, there's some salty language in this video.]

From there, the three start discussing which of the promotional products their characters on the show created would be the most successful on a show like "Shark Tank" – the pen, the egg, the shotgun, the thong, or the towel.

Howerton, who says he can never understand how the "Sharks" make their decisions, seemingly turning their noses up at amazing products, says that the towel would obviously not be their choice since it was the most successful.

"So I think the one that they would pick would probably be Egg, because they would be like, 'Well, no one wants to buy a d*ck towel."

Clearly they did, and it became the nice little revenue stream that their characters on the show hoped it would be for the bar, albeit with much less arguing and screaming and insanity.

It's a funny story, and "Sunny" fans get a fun peek behind the curtain of how one of the show's most famous bits came to be. But it's also clearly a lesson for those in the promotional products industry.

The creators knew they had something funny, so they pursued it. Once they made it, they set it up so it would be available the minute the general public saw it on the TV screen. They also knew that people would be curious about the URL on the show, and would see if it was real. They didn't wait until people demanded the towels, they had them ready from minute one.

Granted, the site crashed, but they clearly still sold enough of them that it was worth their time.

Would the towel have sold as successfully if it came later, maybe a few weeks or even months after the episode aired? Maybe. But the creators of the show knew better and made it in tandem with the episode of the show.

While Charlie's Kitten Mittons were the original "jumping off point," and Frank Reynolds' green egg probably wouldn't be a huge hit in today's promotional products industry, there are certainly lessons for distributors and marketers from the crude towel with a drawing of private parts on it.

The real lesson comes from when the Mac character is explaining to Dennis why the towel works: It has comedy, but it also has functionality — the hallmark of every good promotional product. Also, he points out college kids wearing it in the dorms, meaning he thought about the target end-user audience from the jump. Both the fictional and real-life versions of these characters knew what they were doing with this towel, and it worked.

Don't let anyone tell you that shows like "It's Always Sunny in Philadelphia" aren't educational.