First – what is a Hashtag?
 It is a word or combination of words with a # at the beginning, used to denote a particular topic for discussion. A hashtag allows readers to do searches for specific topics of conversation that are happening now or have happened in the past. It allows the reader to see all the tweets that went through the new stream related to that particular topic.

Here are a couple of examples of Twitter hashtags used correctly:

But why use Hashtags?
Hashtags can help you reach a specific audience on Twitter by using words that relate to your information and to the people you think might enjoy your blog or article. You can also reach people who might be actively searching for that topic for information or discussion.

Hashtags can help diversify your readership. Even though you are reaching out to specific audiences, you will find a wide variety of people who are interested in the same subject – all with their own diverse readership.

It can work like this: one of your Twitter Followers clicks on the link in your tweet and reads your blog. They like it – so they Retweet your original tweet (share it with their own Followers). Now your potential audience has been increased to people you may never have reached before. Watch for Interactions and Mentions on your Twitter Home page. This shows you who has Retweeted your tweets or Mentioned you in on of their tweets.

Make sure you take the time to acknowledge and thank people who Retweet you or Mention you. This also gives you the opportunity to Follow them, if you aren’t already – and they will probably Follow you back, especially since they liked your blog or article enough to share it in the first place.

Using hashtags also allows others who don’t know you to find your tweet through searches for a particular subject. These are people whom you might not ever find or interact with, but now they have found you because of a common interest. It’s easy to start interacting with someone new when you know they are passionate about or care about a topic that interests you too.

What else can Hashtags do for me?
Online mags are constantly on the lookout for good content. It’s tons of work trying to find articles and blogs to post every single day of the week. Most of them use hashtags to find relevant content–searching the Timeline for current news to share.

You can find out what hashtags they use for searches by looking at their Banner at the top of the page. They are usually listed there for readers to search. But only use those hashtags in your tweets if they are relevant!! (see How Not to Use a Hashtag below).

Using relevant hashtags in your Tweets gives you the opportunity to have your blog or article picked up by online newsletters and magazines and posted for that day. Make sure you have your Notifications set up so that you’ll be notified when that happens. And make sure you Retweet the benefactor’s tweet as a thank you. That way you are sharing the news with your Followers –which benefits you as well. Also take the time to thank the online magazine for featuring you. Politeness and professionalism really pay off here in the online community.

How NOT to use Hashtags.
I would be remiss not to mention that hashtags use can also be abused. Don’t do hashtag stuffing  – where every other word in your tweet is a hashtag. This is frowned upon as bad etiquette and can actually hurt you more than help.
Remember: Hashtags need to be specific and relevant to the topic and the audience or they will be viewed as spam. Don’t use a trending hashtag just to try and get readers. If it doesn’t fit your topic or audience, you could lose Followers as well as your credibility.