Importantly, you don't have to leave your posts up for grabs. Story sharing is on by default, but you can switch it off in your settings if you'd rather not take your account private just to limit how others share your posts.

The social network has been aggressively expanding Stories in the past few weeks, including the additions of multi-shot uploads, posting from other apps and hints of soundtrack support. It's not hard to understand why. Instagram has continued to grow rapidly, in no small part due to Stories luring people away from Snapchat and its less-than-successful redesign. If the photo-centric service is going to keep up the pace, it'll want to make Stories as useful as possible -- and sharing posts certainly goes a long way toward that goal.