Cadbury is a leading and one the biggest names in the chocolate industry. They were also one of the earliest and enthusiastic adopter of google+.
Here is what they say about hangouts
What’s different about a Hangout is that it’s eye-to-eye, face-to-face contact. We can’t directly connect with every person who buys our chocolate, but we can connect with some of them. Then, more people see the Hangout, and feel they’re part of the experience. It’s a new frontier — Jerry Daykin, community manager, Cadbury
Quick video about the case study
As of this writing they have over 1.3 million followers and growing. That makes him one of the leading brand on google+ pages by followers.
Business pages and hangouts provide businesses the opportunity to go face to face and connect with customers absolutely free of cost. This is unique opportunity never existed before and now possible through google+.