According to the slides with the watermark “Google Confidential”, Google Plus users will be able to add an analytic code to their profile page and follow the traffic sources, number of visitors, average time on page, etc. The social network statistic data will be measured separately unconnected from other websites attached to the profile owner.
Currently, Google Plus users cannot track the activity of their Google Plus business pages or profiles, except for following the number of shares and counting the “pluses” added to each status.
Recently Google Analytics have announced adding social media reports that will provide statistical data about a website social activity on and off-site. Google are most likely not to receive Facebook and Twitter cooperation.