Google instituted calling through Gmail a day ago, but already it has been a wild success. Unwired View reports that Google has just sent out a celebratory tweet announcing that over 1,000,000 calls have been placed through Gmail in a mere 24 hours.
Calls in the U.S. and Canada are free for the rest of 2010, and calls to the rest of the world start at as little as 2 cents. This news represents an outstanding success for Google. Although some of that staggering number must be due to the novelty of the new system, it's fair to predict that we'll continue to see adoption of this new service spread like wildfire.