Over the weekend Opeara Software announced that close to 3 million users are taking advantage of its new "turbo mode" server-side compression feature, built into Opera 10. While not the first to offer such a feature, Opera does appear to be the largest current deployment of server-side compression in the consumer browser market (dialup providers also used compression in the past).
One promising use of Opera's compression technologies is on metered-connections, where less data means less money charged. Likewise, the compression built in to Opera Mini and Opera Mobile -- browsers built for mobile phones -- also offer similar advantages to users with mobile data plans.
Opera claims in its most recent "State of the Web" report to have 35.6 million Opera Mini users. These customers have viewed 15 billion pages in September 2009 -- roughly 420 page views monthly per customer on average. These page views amounted to 227 million MB of data. As Opera Mini compresses viewed pages by up to 90 percent, this indicates that Opera Mini servers processed close to 2.1 petabytes of data.
The company says that users in its top ten countries -- Russia, Indonesia, India, China, Ukraine, South Africa, United States, United Kingdom, Poland and Vietnam -- save $672M USD monthly and $8.1B annually based on usage charges/the average cost of browsing per MB.