NEW YORK—The hashtag symbol (#), also known as the pound or the number sign, has achieved new meaning since the social media revolution. In its more recent incarnation it can be found gracing Twitter and Instagram feeds, creating an appearance of a secret code to the uninitiated and a sense of order to social media enthusiasts.

Since its original debut on Twitter, the hashtag has spread its influence to other social networks, such as Google+, Instagram, Flickr, Tumblr and most recently, Facebook leading many to ask the question, "Is it time to start using the hashtag?"

Let's start with an explanation of the significance of the hashtag within the social media context and what impact it could have on your social media strategy.

In short, a hashtag preceding a word or phrase becomes a clickable link to that particular topic of conversation. Hashtags serve to aggregate all conversation on a particular topic so users can search and find posts and engage in the discussion on that subject in real time.

How to Use Hashtags
Labeling a topic
When composing a post you simply write the # hashtag symbol (aka the number sign) followed by a topic or phrase, all written as one word (e.g. #hashtagsarecool or #besteyeweardeals). You can post multiple hashtags in a single post.

Searching a topic
When you click on a hashtag that someone else has written, you will be directed to a feed of other posts that include that hashtag. Then you can have a glimpse into what is being discussed about that topic. You can also search for hashtag topics from the search bar in any of the social media outlets.

A Little Hashtag History August 23, 2007 Chris Messina, a social technology expert, is given credit for inventing the use of the hashtag on Twitter when he posted a Tweet suggesting the use of the # symbol to gather discussions about a particular topic (at the time it was for Barcamp, a technology gathering). June 1, 2009: Twitter made the hashtag official by hyperlinking all words preceded with the # symbol. September 2012: Google+ introduces the hashtag feature to its social media platform. June 2013: Facebook introduces the #hashtag feature.

Why Use Hashtags—Visibility and Reach
Hashtags can be a great marketing aid for promotion through social media and now they can be used across most of the social media venues you would likely incorporate into your marketing. If you use Twitter in particular, hashtags create an opportunity to reach and become visible to far more users beyond your typical social reach due to the public nature of the content. Anyone searching for or engaged in that topic or a similar topic could end up seeing your post.

Doing a summer promotion for designer sunglasses? You could use the #designersunglasses tag to make your promotional content searchable for people looking for a deal (such as: Check out our deal for #designersunglasses this summer!).

On the Other Hand...
It's yet to be seen whether hashtags will prove to be as popular and useful to Facebook users. Critics of the latest platform to adopt the clickable hashtag claim that they will be less effective here due to privacy settings that prevent the search from really being public.

Nevertheless, one way that hashtags will be useful is by giving businesses the ability to identify consumers that are engaged with their market or their brand and further focusing their marketing on those discussions.

Start by searching for hashtags that mention your practice (although in the case of an optometrist this is not likely) or terms or products related to your services (#transitionslenses, #greatopticalstore). Further, if you are already using hashtags in a campaign through other channels, you can bolster the campaign by including the hashtags in your Facebook promotion as well.

While hashtags may not be the next big thing in social media marketing, they can prove to be insightful tools. Even if you don't use Twitter or Instagram, it can be helpful to do some research into how hashtags can help your marketing strategy. Play around with hashtags in your posts and see how others engage with them. Do some searches for terms related to your business to see how others use them and what they are discussing. At the very least, now you know what those funny looking symbols mean!

Daniel Rostenne is CEO of EyeCarePro, which helps optometrists grow their practices with online marketing, web and mobile sites and call tracking services.