A hashtag is a word or phrase following a hash sign (#, also known as “pound sign”). It allows users to identify specific content on social networks and helps them navigate posts more easily. Hashtags were first used on Twitter in 2007 and eventually became widespread also through other social media networks like Facebook, LinkedIn, Pinterest, Tumblr or Google+.
Hashtags have become especially popular on Instagram where people use them to tag and categorize their photos. Relevant hashtags can help increase visibility. They can be composed of generic words or statements but also of creative and unique words. In the advertising industry, successful keywords are even used in TV spots, on billboards, or in magazine ads.