Have more than nine members as part of the Google+ Hangout audience

The +1 button is now (or soon) set to allow for sharing on Google+.

Here's a quote from SilconFilter:

Starting today [August 24], though, the +1 button will finally become useful. Over the next few days, Google will roll out an updated version of the button that will allow users to use it to share content with their circles on Google+. The button will also automatically add text snippets and images from any page you want to share, similar to the feature Google introduced on Google Books earlier this month.

I'm in the preview program, so my account is already rolled out. I just used it and it works as advertised.

A mate of mine (not present on this site) has provided a working solution, let me share it for those who might be having the same problem:

Click on the Home button, click "Communities" and you'll see something that says "Community Invitations". Click on the community below, and click " Accept Invitation".