Google's Andy Rubin announced through Google+ and Twitter that "There are now over 700,000 Android devices activated every day." He also notes:

…and for those wondering, 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.

The last figures from Google were 550,000 devices per day when Chairman Eric Schmidt announced it in Germany earlier this year. To put these numbers into perspective, 700,000 devices per day is nearly 5 million per week, 21 million per month and an insane 250,000,000 (or a quarter of a billion) per year.

Let's compare Apple: iPhone 4S sales started strong, with 1 million being sold in the first day and 4 million before the end of the first week. That's for their most popular, top-of-the-line smartphone.