** This was posted in 2011 before Facebook implemented the use of hashtags on their own site. What I discuss here is how people are cross-posting from Twitter and where the hashtags are being seen.
Within Facebook you’ll often see the # sign, also called the hash tag, number sign, or the pound symbol.
Facebook doesn’t actually have a pound sign feature itself. Instead, what you’re seeing are people who have posted a message on Twitter and at the same time have updated Facebook with this same message.
A great example of how this gets done is by using a free program called HootSuite. Hootsuite allows anyone to update their status on social networks like Twitter, Facebook and LinkedIn all at the same time.
If you’re making an update using Hootsuite and you want to make reference to a certain hash tag on Twitter then within your status update you’d use the # symbol. Since you’re also updating LinkedIn and Facebook at the same time, these hash tags simply get carried over to the other social networks.
So just know that whenever you do see that symbol, what you’re seeing is someone who is updating Twitter using a hash tag and has updated Facebook at the same time.