MS Ignite in Chicago was great. Lots of great speakers and lots of News.
On one of the sessions they showed of the Skype for business Broadcast function that comes in Skype for business Online.
From this feature you can have "Meeting" With upto 10000 People and also record it so that it can be downloaded later.
When using the broadcast function, all sound and what you show off is 20 secunds delayed. And it will play off in Your webbrowser.