A hashtag is a way to unite global Tweets around some particular topic.— Search Engine Journal
For those not yet familiar with the term, a hashtag is a tag prefixed with the # sign used in a Twitter post (or other messaging service), which is intended to aid searching tweets on a particular topic.— Binary Law
For those AIM readers unfamiliar with Twitter, a hashtag is a key word or phrase with a number sign at the beginning.— Accuracy In Media
What sort of insight to you gain from following the Stern Show? depicting his bulldog, "Bianca Jane Romijn Stamos" ignoring him in Central Park hashtag (#) to their tweets, so that they're easy to aggregate with other, similar posts.— Buffalo Pundit

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