The Duo team began rolling out a series of very funny promotional videos to help promote the app. The app to date has seen over 10 Million downloads from the Play Store alone, so usage is starting to pick up.
You all may have even seen an increase in your own contacts showing up as users of the Duo App.
Below are some of the videos. More can be found on Google's Youtube page here: https://www.youtube.com/user/Google/playlists