One of the most useful aspects of Twitter are hashtags. Effective and clever use of hashtags can really make Twitter’s role as an information aggregator shine, and can also be used to spread your messages to a larger audience. While simple in concept, hashtags can often stump relatively new users or clients seeking to use Twitter for business purposes.

What’s a Hashtag?

A hashtag is a way to join common topics together in Twitter. You enter the hash mark (#) before a word or phrase to create the keyword; omit spaces or replace them with underscores to grab the entire phrase. The hashtag then becomes “clickable”: Twitter users who click on a hashtag will see a real-time stream of everyone who’s used it in their posts.

Hashtags are commonly used for events and online discussions or chats. Whoever organizes the event or chat will assign a hashtag in advance for use by the participants. This insures that anyone who wants to join in will be heard in the ongoing conversation (for some recent, good examples, look up #twtrcon or #uiewamt). You’ll often notice that your followers will increase after participating in these types of chats (just don’t post for that purpose alone; be informative, helpful, and polite).

Hashtags are also useful for joining together communities of interest. If you tweet something about user experience, for example, your messages will only reach your followers (unless they decide to retweet you, of course). But adding the hashtag “#ux” will carry your message to anyone tuning into that discussion, which can often be a much broader audience. In addition, by following community of interest discussions yourself, you’re likely to come across helpful and valuable sources of information. It’s also a great way to make new connections with folks who share your passions.

How Do I Use a Hashtag?

The most effective way to use a hashtag is to find one that’s already in use; that way, you’re confident that your messages will find their way into existing conversations. Go to Twitter’s search page and enter a sample term to see whether it turns up any results. There may be more than one term for a specific topic (such as “#ff” and “#followfriday”). If you’re at an event, check with the coordinators to see whether an official hashtag has been assigned.

If you’re thinking of creating a new hashtag for a business purpose, make certain it will have common, consistent, and frequent use by any accounts managed by your organization. It’s important to check whether your chosen hashtag is already in use to avoid confusion.

Some users will make up their own hashtags for a whimsical or clever purpose. Foes of the font Comic Sans (myself included) will occasionally post using the hashtag “#deathtocomicsans”. Social media luminary and frequent traveler Olivier Blanchard (also known as The Brand Builder) uses “#WhereisTBB” to let his audience know his location when on the road. These may be less practical, but they’re often a lot of fun.

Best Practices for Using Hashtags

When using hashtags, be mindful of some etiquette rules that have been established:

  • Choose wisely: Don’t use more than three of four hashtags in one post; not only is this a technique of spammers, it also reduces the length of your message (make clever use of all 140 of those characters!).
  • Stay on topic: Don’t use hashtags for unrelated posts. During the Iran election protests last year, the hashtag “#iranelection” was used, where it resided as one of the top 10 trending topics for several months. An intern at a British furniture store capitalized on this hashtag’s popularity by using it in their Twitter promotions, and they were promptly slammed for this tactic.
  • Don’t overshare. It’s one thing to be a chatterbox in your own feed, but when you join a hashtag conversation, you’re adding your voice to others who don’t normally follow you. Don’t irritate your new neighbors by posting too frequently. If you’re not sure how much is too much, see how often others are posting and use that as a guide.