Instagram offers two interesting ways to hack growth. First, for a product or service that is not tied to the Instagram API directly, there are a number of growth hacks to spur brand engagement and drive prospective customers down the conversion funnel. Second, Instagram has a powerful API for developers to build mobile apps on top of the social platform. And as a result, there are a number of ways to included built-in growth automation into your app. Starting with the onboarding flow and expanding into growth features that can be anchored into "light bulb" user interaction with your mobile experience. Among the many hacks you might have seen out there, be it in a B2C or B2B context, which ones have been the simplest yet most powerful in your opinion?