Audience engagement is one of the most challenging aspects that popular social networking sites are constantly faced with. And the only way out seems to be regularly upgrading the existing array of services, which may hopefully benefit or add up to the user experience. The challenge remains the same, whether you are ranked first or tenth in the hierarchy of top social networking sites. And Facebook , the No.1 ranked Social Networking site ensures that it’s constantly coming up with new features to keep the audience interested.