2. Justin Bieber
Twitter handle: @justinbieber
Joined Twitter: March 28, 2009
Followers: 29,804,326
First tweet: May 12, 2009. "Check out my single 'ONE TIME' on my myspace and spread the word for me. Thanks www.myspace.com/justinbieber"

Nope, not going to go into this Canadian pop fameball's career.

Why? Because this is a Twitter story and few people have meant as much to Twitter as Justin Bieber. He once accounted for 3% of all Twitter traffic. Twitter tweaked its trending algorithm just so non-Bieber breaking news topics would have a chance.

It's not that an 18-year-old with three albums to his credit has influenced the direction of an entire social networking site. His millions of fans have, and it made Twitter and marketers alike take notice. Don't underestimate the power of a teen pop icon.

If you liked this article you might like

How eSports Leaders Are Making a Business Out of the Professional Gaming Market

Why Amazon's Reported Smart Glasses Might Be Just a Niche Product -- For Now

How PayPal's CEO Uses Military Level Karate to Succeed in Business