Well, I found my answer … when a hosting is applied the users load a special file on the page and these “viewer” are counted. The problem is that aren’t users. that are just people that load this file. So if I want to, I could produce “Now hosting for 1000 viewer(s)” if I wanted to.
However your timeout is too short. The hosting command is pushed to the client, but depending on the latency and on the device itself it usually takes much longer to host a channel. So in average over multiple days you can say that only 60 % or less of all real viewers are counted. I would suggest that the timeout should be higher to make the results much more reliable. For the hosted channel it does not make a difference if he gets the message 5 seconds later but it can be really annoying for a hosting channel when you have 100 viewers and only 60 are counted for the hosting.
And there is still another problem with the hosting. See this log:
18:17 Now hosting GeezertheGozerian.
18:18 geezerthegozerian has gone offline. Exiting host mode.
18:20 Now hosting tlovetech.
18:28 geezerthegozerian has gone offline. Exiting host mode.
Anybody seeing the problem here? 
And this problem is not new as I reported it over 2 weeks ago, see … https://twitter.com/Efficiency_VI/status/659356325315407872