They're so ubiquitous we use them almost as a matter of course, but how much do we really know about the humble hashtag? It turns out there's a lot more than some squiggly lines to the socially synonymous symbol. 

Here's some facts you may not have known about hashtags.

Numbers game

The hashtag is actually a reworking of the traditional numbers or pound symbol, and was originally known as the hash symbol.

In the early days of the internet the symbol was used in IRC (Internet Relay Chat) rooms to denote different topics and channels.

But it wasn't until IRC user Chris Messina decided to use the symbol to identify and tag topics on Twitter.

In 2007 he posted the first tweet containing a hashtag with:

"how do you feel about using # (pound) for groups. As in #barcamp [msg]?"

Growth

It turns out users were very interested in using hashtags to organise content on Twitter.

The hashtag first showed its political power when used in force during the Iranian election protests of 2009.

The same year Twitter started adding hyperlinks to hashtags, so users could search for associated content.

Play ball

The hashtag's popularity continued to grow. in 2011 Canadian Prime Minister's crime policies were referred to as "a hashtag fail" by an opponent.

Kanye West created the "hashtag rap", a sub-genre of rap that consisted of three elements: a metaphor, a pause and a one-word punch line. 

In 2013 Twitter announced its initial public offering with the hashtag #TwitterIPO.

Bird's Eye recently released a mashed potato in the shape of @ symbols and hashtags called "Mashtags".

Money talks

Ttweets with hashtags see double the interaction of those with none.

And the sweet spot? Research suggests that two hashtags is the optimal amount per tweet. 

Top tags

The most popular all time hashtags include the MTV Video Music Awards' #vote5sos (78 million tweets), #WorldCupFinal (32.1 million tweets), #JeSuisCharlie (5 million tweets), and #IceBucketChallenge (4.2 million tweets).