This document discusses how Twitch extensions, drops, and commerce integration can help engage communities on Twitch. It provides information on overlay and panel extensions, drops programs that reward players for watching streams, and selling games directly through a commerce system on Twitch. Examples are given of popular extensions, large drops campaigns, and the fulfillment process for in-game entitlements purchased through Twitch. Contact information is also provided for the Twitch developer site and commerce team.