In response to Facebook’s unveiling of video for Instagram, Forrester Principal Analyst Nate Elliott notes that Facebook has always borrowed heavily from other sites — and has done so with great success. “For instance, when Twitter was just gaining momentum, Facebook redesigned its newsfeed to allow for Twitter-style rapid conversations. And when Foursquare started to make waves, Facebook introduced a check-in functionality (that lives on today in users’ ability to tag their status updates to certain locations).”

According to Elliott, adding Vine-like functionality to Instagram is just the latest example of Facebook grabbing a feature from a small social competitor and offering it to hundreds of millions of its own users. “This model of ‘borrowed innovation’ has worked well for Facebook — bringing interesting new features to audiences that the social startups can only dream of. It also keeps Facebook’s services fresh and is one of the reasons more than a billion people still use the site every month.”

For additional analysis from Forrester Principal Analyst Nate Elliott, visit his blog here.