"There is a reason for this madness and that is the waterfall." - Roger Steen
The New Volume SliderGoogle+ is rolling out a volume slider to better control your main stream. I discovered it by accident, when checking out page management features. I'm not positive, but I think it's a roll out because the circles of the page had the volume slider and my personal circles don't have it yet. Of course, I still don't have that fancy new navigation bar either....
I later found a complete explanation on gplustuts which turns out to be a very informative site with a rather unfortunate name (as if there isn't I'm sure there will soon be a site called gplusluts or gplussluts). For a thorough understanding of the volume slider thing, check out the linked article.
Basically, the volume slider works like this:
You select a percentage of posts from each of your circles that make it to your main stream.
How, exactly, it picks and chooses which posts from that circle make the percentage cut isn't particularly clear to me (though I didn't watch the video). If you give a circle 5%, it may show you 5% of the posts from each poster in that circle in your mainstream - or it may just put every 20th post from that circle in your stream.
Main Stream Waterfalls
This, undoubtedly, is to help people like me. My main stream is like a waterfall. You may have shared a fabulous post I would have loved to have seen - but if I wasn't watching my stream within the hour or so you posted it, by the time I look at my stream again your post will probably be long gone.
I recently conducted an Experiment to get a rough idea of whether a single post was reaching enough of the people who have circled me, or if I'd have to share multiple times to get the word out about something I thought was important.