I've noticed that sometimes in my Avast forum topic reply emails, when the Avast Developers Google+ profile page is visible on the right, there are some sort of adverts/notifications of different things, like in the latest there's stuff about "VEE17 Summit". If I put my mouse over it, the browser displays the link itself being URL shortened link, in this case by "buff.ly". Is Gmail showing me messages from Avast's Google + group?