Zynga lessens its Amazon dependency

Zynga(s znga), the newly public company behind Farmville, Mafia Wars and other games played by gazillions of people, is relying far less on Amazon’s(s amzn) public cloud than it has in the past.

On the company’s fourth quarter earnings call Tuesday, buried in the numbers about growth of daily active users, monthly active users and monthly unique users was a little bombshell: Zynga has already moved a huge chunk of its workload from the Amazon cloud — which it has used extensively — to its own Z Cloud private infrastructure. Z Cloud relies on Rightscale as the management layer along with Cloud.com(s ctsx).

“By end of last year, nearly 80 percent of [daily active users] were hosted in Z Cloud versus 20 percent in the beginning of the year,” said John Schappert, Zynga’s COO. He did not name Amazon, but Zynga has said publicly that it relies heavily on Amazon Web Services compute power, especially as games launch because it’s hard to predict their demand.

From that you could extrapolate that in early 2011, Amazon ran 80 percent of those launch loads and now runs just 20 percent of them. That’s quite a swing.

Later on the call, Zynga CFO Dave Wehner said the company experienced increased third-party hosting costs this year. “We expect them to decrease as we roll out of those arrangements. We plan to transition more of our game traffic to Z Cloud this year.”

When Zynga launched Farmville in June 2010, it had run out of data center capacity and so it turned to Amazon’s public cloud in an arrangement that Zynga later called fortuitous.

Over the past year, Zynga has talked up its plan to build out more of its own Z Cloud infrastructure and moved more of its games in house over time, but it never provided any metrics. It has said in the public filings leading up to December’s IPO that it considers its home-grown Z Cloud to be a competitive advantage. 

Zynga is nothing if not fast growing; daily active users grew 13 percent to 54 million from 48 million year over year for the fourth quarter. Monthly unique users grew 23 percent to 240 million from 193 million for the same period. Monthly unique users increased 38 percent to 153 million from 111 million. Putting more of that work into Z Cloud could be seen as a big risk if it weren’t for the fact that the work could once again be routed to Amazon if demand outstrips Z Cloud’s capabilities.