The Apple iPhone is displayed at the Verizon Wireless store at Jefferson Pointe in Fort Wayne, Ind. (AP Photo/The Journal Gazette, Laura J. Gardner) ** THE NEWS-SENTINEL OUT ** (Laura J. Gardner/AP)

In a blog post, the ad agency said the data it uses for the tracker is the average of a 24-hour rolling period, updated hourly. Tuesday afternoon, Verizon showed it had 12.7 percent of all iPhone Web usage. The post was later updated to say that some of the servers had gone down, so if you’re trying to check out the numbers yourself, they may be a bit muddled as the servers repopulate data from the missing hours.

The site has been tracking the growth of the Verizon iPhone since its launch, noting that the phone took 3 percent of the iPhone market within 24 hours of its release and 6 percent within two weeks.

Verizon has yet to release firm sales numbers for its version of Apple’s phone, but the company did announce it set a first-day sales record when the handset debuted in February. That’s led some analysts to speculate that the company’s sold about a million handsets.

The jury is out on which of the two models of the iPhone 4 is better . Data tests seem to generally indicate that AT&T has much faster data download speeds, but Verizon is the more reliable network.

Did you switch to a Verizon iPhone, or just wait until AT&T was not the only option? How does the service compare?

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