Google SVP of Mobile Andy Rubin has just tweeted that Android device activations are now 850,000 units per day. This number is 150K more than the last known 700,000 units per day in December.

At Mobile World Congress in Barcelona.Enjoying watching the ecosystem at work.850k activations a day now!

— Andy Rubin (@Arubin) February 27, 2012

Here is a quick chronology of Android device activation numbers:

• December 21- 700,000 devices
• July 15, 2011 – 550,000 devices
• June 28, 2011 –  500,000 devices
• May 10, 2011 – 400,000 devices
• Feb 24, 2011 – 350,000 devices
• Dec 9, 2010 – 300,000 devices
• Aug 4, 2010 – 200,000 devices

If you don’t know how Google counts the device numbers – here is an explanation from Rubin – We count each device only once (ie, we don’t count re-sold devices), and “activations” means you go into a store, buy a device, put it on the network by subscribing to a wireless service.

More Facts from Andy Rubin’s Google Plus post:

There are over 450,000 applications in Android Market and our partners have activated a total of 300 million Android phones!