Instagram celebrates its 1 billion user mark with launch of YouTube rival IGTV

Instagram today marked reaching one billion users with the launch of a recently rumored long-form video service called IGTV.
Users can access IGTV via the original Instagram app, but also through a standalone app starting next week. Content on IGTV has a time-limit of an hour, and during a conference on Instagram Live, the Facebook-owned platform has already piloted the new service with influencers and creators.
Another unique feature of this app: it has been formatted so that all vide