Oliver over at TechCrunch (and late of this very weblog) has posted an interesting piece about the effect that Opera's mobile browser has had on operator revenues.

Most significantly, and in direct contradiction of operator's fears, the use of the Opera browser - which circumvents the "walled garden" that many operators attempt to maintain as a means of further monetizing data customers - is clearly increasing the ARPU that operators receive based upon customer data usage.

The press release from Opera with details of the report also says that the browser has increased the number of people using mobile web browsers, and the interest in browsing outside operator's own portals.

Since T-Mobile started offering Opera Mobile to deliver the full Internet on their smartphones in 2005, the mobile browser has proven itself to be a compelling revenue booster. During the first few months after the launch of web'n'walk in June 2005, an average web'n'walk customer was visiting 330 Internet pages per month. This resulted in an increase of 489 percent in data volume per user and 119 percent of data ARPU (excl. SMS) per user. T-Mobile will now offer Opera Mini on their high-volume feature phones, providing full Web access and increasing ARPU across their entire customer segment.

"Smartphone owners have already shown the potential of full Internet services to boost ARPU," said Tony Cripps, Wireless Software Analyst, Ovum. "Now mobile operators can extend that option across their customer base and free users from the confines of the walled garden."

So, quite apart from the fear that allowing users outside the operator portal would reduce potential revenues, the opposite effect is appearing. Unsurprising really.