If you’re not much of a Twitterer, you may not know what hashtags are, but if you’re trying to sell books, it’s something you should know. When people tweet, you’ll often see words either in the tweet itself or appended to the end of the tweet which are preceded by the pound sign, also known as the hash or number symbol (# – the character above three on a keyboard). In Twitter, words with this symbol are identified as search terms for a tweet, in much the same way as tags are used for articles, blog posts, or products on Amazon (see my post on book tagging for more on that topic). When people tweet with hashtags, they help searchers locate tweets that are related to what they’re looking for. For example, you can append #book, #ebook, #kindle, and/or #nook anytime you tweet about books, ebooks, or ereaders. People who are looking for information about any of these, can search within Twitter or on Twitter-related sites like Twubs, Twibes, or Topsy for all tweets with those hashtags. This system takes the overwhelming mish-mash of sound bites that is Twitter and turns it into a useful, organized directory of information. One hashtag that is particularly useful for authors is “#samplesunday”. This hashtag is the brainchild of author David Wiseheart, who first proposed its use on his blog, “Kindle Author”. The point of #samplesunday is to post an excerpt of your writing on your website, and then tweet about it with the hashtag #samplesunday. You can then search for Sunday samples, read them, comment on them, and of course, retweet them. It’s a quick and easy way for authors to spread the word about their work and show it off to those who are looking for something new to read for the week. I’ve used #SampleSunday several times, and it always increases traffic to our book pages, so I highly recommend it as a book marketing method. Why not try it yourself this week? Here are some of our samples from past #SampleSunday’s.