The inexorable rise of the humble hash

The humble hash (#) sign has done alright these past few years (I realise my North American friends may still persist in referring to it as the pound sign or even the number symbol, but to me it's hash).

For many years hash sat on the digital sidelines and watched as its flamboyant neighbour the 'at' symbol (@) embedded itself in billions of email addresses across the globe. Even the modest but jauntily optimistic forward slash (/) got in on the internet action (though it still liked to work in pairs). But little old hash sat there on the keyboard (or not if you were using a Mac) like an italicised, empty noughts and crosses game, largely ignored.

But with the arrival of social media - and specifically Twitter - the hash found its place in the digital world. And it's not an insignificant one, because it's central to discovery (which in many ways these days is as important as search).

For those who don't know (I'm sure there are some) the hash symbol is used in hashtags: words and phrases prefixed with # which link the content with which they're used to a particular subject. So, for instance, I might tweet "Messi's having a decent game" and use the hashtags #FCBarcelona and #UCL to associate the tweet with the social conversation around Barcelona football club or the Uefa Champions' League competition. The key thing is, anyone with an interest in either subject can search on the hashtag and find all the content which is using the same tag. Useful.

What's less useful in my view, particularly on Twitter, is when people make up hastags to add an ironic or explanatory twist to their tweet. For example, "Found it really difficult to get out of bed this morning. #13thglassofwineamistake". I'd be happy if that little practice stopped.

The hashtag has quickly become established in social media, not only on Twitter but on other social platforms too, including Instagram, Google+, Tumblr and Flickr. And perhaps most significantly, since yesterday, the daddy of all the social networks, Facebook, has enabled the use of clickable hashtags.

This is quite important. Personally, I think social discovery on Facebook has been one of its huge weak points. Its search engine is poor (to say the least) and the chances for finding content around topics of interest have been scarce. Hashtags could change all that.

Basically, by clicking on a hashtag used by one of your friends on Facebook - or a brand you follow - you'll pull up content tagged with the same hashtag, whether you're friends with the individual or a fan of the brand that posted the content or not.

There are a couple of important implications here:

1. If you're using hashtags as an individual, you need to be very sure that you're happy for the content you're posting to be discoverable beyond your social network. This is particularly important if you've linked accounts on other networks like Twitter and Instagram to your Facebook profile, as they'll be searchable on Facebook too.

2. Brands will start using hashtags like crazy. Possibly to an increasingly annoying degree. Some hashtags will become incredibly popular (for instance #funny #fail #lol #cat) and brands will attempt to use that popularity to make their content more discoverable by more people. But they need to be careful to ensure that the content they're posting genuinely relates to the hashtag.

Interesting times. The humble hash is like the unknown kid suddenly discovered and thrust into the limelight. I just hope it doesn't end up like Justin Bieber.