Facebook is testing whether to follow Twitter's lead and allow users to click on a hashtag to pull up all posts about similar topics or events so it can quickly index conversations around trending topics
Facebook Working on Incorporating the Hashtag - WSJ.com: Facebook is working on incorporating the hashtag, one of Twitter's Digital Media Modern Invention.
This will allow Facebook to target ads across their social graph, and help the company to monetize its Facebook Advertisements and sponsored stories , where users liking a story might be targeted or re targeted to show similar advertisement, and group them as a symbol to store and and archive conversations
However Facebook is yet to comment on what exactly its planning to do with " Hastag" symbol. This might pit Facebook and Twitter against each other as both fight it out for a pie of lucrative real time search , as a large amount of data could be structured and classified with the intent of providing real time personalized search as well as running contextual advertisement againts keywords which could power other social networks as well as third party real time search providers
Instagram, which Facebook acquired last year, already uses hashtags, allowing users to sort photos by the symbol