If you +1 things and use hangouts, 'using Google+' is exactly what you are doing... You might only be at the bottom rung of MAU's with a tiny level of engageme

If you +1 things and use hangouts, 'using Google+' is exactly what you are doing... You might only be at the bottom rung of MAU's with a tiny level of engagement, which if common would be easily identifiable by looking at other metrics. So it's possible they are purposely deceiving us with misleading metrics - but you are indeed a G+ user. Albeit, not a very valuable one.