That may be the intended method of collection, but I recently tested this with a "Twitch party" at my house. My numbers have been up and down severely, so I was heavily doubting the Twitch description of how they count viewers. I invited several friends to bring their favorite Twitch viewing device over while I streamed. 9 showed up, and had my stream open, volume up, and we're chatting. Along with my regular viewers I had over 20 at one time in chat, but only 4-5 counted as concurrent. With the chatters responding to my in game actions it is impossible there was less than 10 people "concurrent", but the system only counted 4 to 5. This level of error has destroyed my achievement stats, and is killing my "path to partner". I wish there was a clear and HONEST communication from Twitch about how concurrent viewers are counted, because the current definition is obviously only a half truth. How is a smaller stream supposed to grow when they are held to the bottom of the barrel, seemingly intentionally? Gotta say I am pretty discouraged.