Google+ has a new feature rolling out that allows you to quickly see how posts you have made are being received. Called Your Influence, it is found on your Google+ profile next to the About button. There you will find an overflow menu (the three vertical dots) which you can tap and then see your stats. The stats can be viewed for the last 7 days or the last 30 days and give you a lot of information about how many new followers you have, how many new collection followers you have for your collections and the influence of your posts.
The feature is rolling out now so it make take a few more hours for everyone to see it.