When did the hashtag become such a big phenomenon and most importantly, why do we do it? The popular use of hashtags has earned them a seat in the Oxford Dictionary. “Whoop whoop!” Hashtags are used to categorize social media posts seen on almost every social media outlet today. Hashtags first took notice on Twitter in 2007 (Adweek) for highlighting keywords within discussions in 140 characters or less. Now, Facebook, Instagram, and Vine have caught on to the hashtag frenzy!