It's the first thing you see when entering Facebook's campus in Menlo Park, Calif, and without a doubt the image most closely associated with the social network.

The Facebook Like icon, with its iconic thumbs up design, launched in early 2009. The following year, Facebook launched the Like button for other websites. By the end of last year, Facebook's Like and Share buttons were being viewed more than 22 billion times a day.

"We didn't anticipate that it was going to be such a cultural icon," Soleio Cuervo, an Facebook product designer behind the Like icon, told Mashable in an interview for a longer piece looking back at the social network on its 10th anniversary.

As it turns out, the Facebook team debated a number of other designs for the Like button before settling on the one so many recognize today.

"We had a green thumbs up. We had a heart. We explored stars," he says. "But they were all just sort of generic."

Cuervo had decided he wanted to use a hand gesture to make the Like function to "differentiate" it from "its counterpoints on other services," but that led to one notable complication: In some regions, a thumbs-up gesture is viewed as an insult.

"There was discussion about localizing it because a thumbs up in other cultures is a profanity," Cuervo says. "I dug in my heals on that. That is a way to demonstrate that Facebook is here to stay."

Cuervo won out. The thumbs up icon still exists on the social network, although three and a half years later, Facebook decided to ditch the symbol on the Like button in favor of a more generic "F" logo.

By that time, Cuervo had already left Facebook and joined Dropbox. Even though he's no longer with the company and the button's design has changed, he says some still associate him with the thumbs up.

"My little brother is great at kicking me down a notch, keeping me humble," Cuervo says. "He says, 'You're the biggest one-hit wonder of all-time. You're Thumbs Up Guy.'"

On a serious note, he shrugs off credit for making the original Like button's design iconic.

"The reason why the Like button is so iconic is not because of the work I did," he says. "It's a testament to the company's success."

BONUS: 8 Facebook Cynics Who Doubted the Company's Direction