We all use them, some of us much more than others. The number symbol - or pound sign, depending on the context and region - originally gained its social prominence on Twitter. Over time, it's become the de facto standard for tagging and grouping relevant topics together throughout social media.
In most cases, a hashtag makes your social update clickable and thereby interactive, enabling other users to follow a conversation, event or other trending topics. But hashtags create a lot of noise as well, with many users unavoidably slipping into the habit of crafting long-winded jokes or jabs following a hash. #SoDontOverdoIt.
"The hashtag has kind of become a little bit like a running joke," says HubSpot chief marketing officer Mike Volpe. "I feel like people are generally overdoing it."
The evolution of the hashtag
Before discussing how to use hashtags for the utmost benefit, it's worth understanding what exactly is a hashtag and how its role in social media has evolved.
Stacy Minero, head of content planning at Twitter, describes hashtags as a simple way to group conversations.
"If somebody puts a hashtag in front of a trend or a topic, they're assigning some personal meaning to it." she said.
"That means that others can search the hashtag, they can follow a conversation or they can join in. It's a gateway to discover something that's entertaining or inspiring," and it lets you "catalog conversations."
Facebook comes late to the hashtag party
Facebook didn't formally embrace hashtags until last June, almost six years after the first hashtag appeared on Twitter. But the leading social platform has come around, defining hashtags much the same - an easy way to discover and join conversations about specific topics.
"When we discovered the large volume of people using Facebook to discuss things going on in the world around them - like news, sports and entertainment - we became excited about building a product to make it easier for people to discover and join those conversations," says Allison Swope, product manager at Facebook.
While the definition of hashtags hasn't evolved, adoption among both consumers and marketers has changed over time. "From an advertising standpoint, we're seeing more versatility in the way that hashtags are being utilised," Minero says.
Marketers increasingly anchor their brands to hashtags by creating content around specific events, or by developing participatory programs that invite people to discover or create content.
"We're seeing brands start to integrate hashtags as part of a holistic campaign. You'll see them plugged into TV spots [and] incorporated into print and even into out-of-home advertising," Minero says.
"It's become more like a cross-channel call to action versus something that just sits within the social space."
Says Swope: "If we think about hashtags as a way to organise content into a large conversation, then we can think of brands and other partners as hosts, and the people who are posting as participants. The interests of both parties are very closely aligned."
Brainstorming the best hashtags
In most cases, Volpe says, hashtags should be used around a very specific conversation bounded by both topic and time - a conference or other event, for instance.
At the same time, a unique call to action can generate "awesome content" associated with a brand or product, Swope says.
"Not only will your hashtag reach more people if attached to engaging content, but you'll also generate content that can be used across other platforms to make the story you're telling richer and more relevant to your audience."
While the general thrust of a hashtag is similar across all social media, the context in which these platforms are used should guide the most appropriate use. Facebook and Twitter both shared advice with CIO.com for the best use of hashtags on their respective platforms.
Hashtag tips from Twitter
"Our core users are driven by three motivations: Self-expression, human connection and content discovery," says Twitter's Minero. "There's a continuum when you think about hashtags. You can plan for them. You can also do live social response."
Minero shares these four tips for Twitter hashtags:
Hashtag tips from Facebook
Facebook's Swope says using hashtags that are too long or complicated, or that change too frequently, "will hurt the volume of content you're able to generate and, therefore, the total reach of your campaign."
She identifies three best practices and strategies for hashtag use on Facebook:
For all that hashtags give brands, they can also take much more away.
"You need to be cognisant that hashtags dont belong to you," says Volpe. "A lot of brands think the things they create belong to them. They belong to no one, so they can easily be hijacked. The community can ... take it in a direction that you might not want to go."
For example, when the New York Police Department asked Twitter users to share photos with officers and tag them #MyNYPD, many posted photos depicting acts of alleged police brutality. The NYPD quickly shut down the campaign.
Applied appropriately, hashtags are a useful tool, but theyre definitely not the be-all and end-all, Volpe says. "You can be very successful in social using no hashtags - and even if you are successful in social with hashtags, you probably use them very sparingly for the right purpose."