To begin with, the Periscope app on Android and iOS now has an activity tab that tells you both about new followers as well as people watching your replays. If you're curious to know what kind of audience you're building, it should be easy to figure out. Not detailed enough? On the web, you now have access to an analytics dashboard that gives you detailed stats for your videos. You'll know which videos reel in the biggest crowds, how long people typically watch and other useful tidbits that could influence your strategy. The dashboard will only be of limited help if you're an everyday streamer, but it could be vital if you're streaming for a company or otherwise take your Periscope sessions very seriously.