The use of hashtags for social media marketing is nothing new.

But, we wanted to provide a one-stop resource that tells you if you should use hashtags, how many hashtags to use, where to find trending hashtags and what kind of exposure hashtags can give you across Facebook, Twitter, Instagram and LinkedIn.

Don’t feel like reading about the history of hashtags from way back? Skip to the section that matters most to you.

Facebook

Twitter

Instagram

LinkedIn

The History of the Hashtag

Where did the hashtag come from? It looks like the hashtag came into existence sometime around the 14th century. Before it was used on telephones and Twitter, the hashtag came from “lb,” the Latin abbreviation for “pound.”

So we (in the U.S.) called it the pound sign for a while.

According to dictionary.com, the hashtag’s official name is the octothorpe, a name invented by telephone technicians when they added the symbol to telephone keypads.

It wasn’t called hashtag until its usage became popular on social media.

The hashtag's usage as a way to find posts about a common topic comes from the below tweet from 2007, suggesting that people used hashtags to create groups on Twitter.

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

— ChrisMessina (@chrismessina) August 23, 2007

From there, the hashtag began to build momentum, eventually becoming the social media marketing powerhouse it is today.

Well, now that we know how the hashtag came into existence, we can talk about how to use hashtags on each social media platform.

How to Use Hashtags on Facebook

Using hashtags on Facebook can get your posts more exposure, but you have to use them the right way.

Here are some tips for using hashtags on Facebook:

1. Don't use too many hashtags. That will make your business look annoying and/or spammy. Instead, go for 1-2 hashtags per post for the best engagement. If you use more than two hashtags in a Facebook post, you'll see less engagement.
2. Make your Facebook post public (and make sure to allow people to follow you). Otherwise, only friends and followers will see your posts with hashtags. When you make your Facebook post public, it will allow anyone to see the post if they search for a hashtag that you've included in a post.

How to Use Hashtags on Twitter

Tweets with hashtags tend to get double the engagement of tweets without hashtags. But, as usual, there are rules about using hashtags on Twitter, including how to use hashtags in Twitter ads:

1. Tweets with 1-2 hashtags get 21 percent more engagement, so don't go overboard. Just a couple of hashtags in your tweet should do the trick.
2. Tweets with hashtags receive more retweets, but tweets that specifically ask followers to "retweet" (not "RT" - you have to spell it out) will get you even more retweets!
3. Be careful using hashtags in ads on Twitter. You'll probably get more ad clicks if you don't use a hashtag.
4. Twitonomy is a great resource to find analytics for trending hashtags.

How to Use Hashtags on Instagram

If it seems as if the sweet spot across all social media platforms is 1-2 hashtags, this is not the case on Instagram. That's probably why so many Instagram posts have seemingly endless hashtags.

Here are some tips for using hashtags on Instagram:

1. Always use hashtags on Instagram. You'll get 12.6 percent more engagement on average.
2. You can go a little hashtag wild since Instagram posts with 11 hashtags get more engagement than posts with zero hashtags.
3. In this case, more might just be better. According to Hootsuite, you can use up to 30 hashtags on Instagram.

How to Use Hashtags on LinkedIn

LinkedIn hasn't always supported hashtags, but, LinkedIn hashtags are back. You can use them in pretty much the same way you'd use a hashtag anywhere else.

People can search for hashtags on LinkedIn in the same way they can on other platforms, and LinkedIn uses hashtags to monitor what's important to users so it can show them more relevant content.

This is how you should use hashtags on LinkedIn:

1. Add hashtags to your business's profile to give you more visibility on the networking site.
2. If you write LinkedIn Pulse (LinkedIn's blogging platform) articles, add some relevant hashtags to the body of your article.
3. LinkedIn doesn't have a limit of hashtags that you can use, but you shouldn't go hashtag wild as you do on Instagram! We suggest keeping usage under five hashtags per post.

More Tips for Using Hashtags for Social Media Marketing

As with all things marketing, you should do a little research on hashtags before you go throwing them into every social media post you publish for your business.

Look at what your competition is doing with hashtags. Are they using any at all? Do they bombard their followers with hashtags? Or, is their strategy driving customer engagement? If they're doing a good job, try to mimic what they're doing for a while until you get the hang of it. Then, build your own hashtag strategy.

Wherever you use hashtags, they cannot include special characters, such as #digital+marketing. Your hashtags need to be all one word without special characters and spaces. 

And don't forget to use hashtag research tools to give you the best chance at maximizing your hashtag usage. Here are some research tools.

Hashtag Research Tools

Not sure what your hashtags should say? Here are some tools to help you get started:

1. Ritetag - I used Ritetag to find hashtags with high engagement rates when I managed our Twitter account.
2. Twitonomy - I mentioned this earlier, but in case you missed it, Twitonomy will monitor Twitter hashtag analytics for you.
3. Hashtagify - This is another tool that will help you find trending Twitter hashtags