Google Inbox has been extremely popular lately. Tens of thousands of people are trying to get their beta Inbox invitation. Some people are purchasing invitations on eBay. Others are getting their invites from friends. Others are looking around on Google Plus for invites. So, how do you get them?
Google as a page on Google Plus called “Inbox by Gmail”. They have been occasionally giving out invitations for an hour at a time with the hashtag #InboxHappyHour.
To stay on top of these happy hours you could add the page into a notifications circle. Then, whenever they have Inbox news or offer a Google Inbox invitation youwill know. Their page is here: Inbox by Gmail.