While confirming the Nik Software acquisition on his personal Google+ account, Senior Vice President of Engineering Vic Gundotra just revealed a few interesting Google+ statistics.

The Google executive announced 400 million people have now “upgraded to Google+,” with 100 million of them being “monthly active users” on desktop and mobile. These rounded numbers directly refer to Google+ and do not seem to encompass users actively exercising other Google products.

Google typically avoids dishing out specifics on Google+, like active user base estimates, but it has previously cited the budding network as the social core to its umbrella of products and claimed it boasted more than 170 million users (of which 60 percent allegedly sign in daily).

It is further interesting Gundotra chose to reveal Google+ numbers alongside the Nik Software buyout. The combination seems to support 9to5Google’s earlier inkling about the acquisition possibly helping Google+ contend with Facebook and Instagram.