Dive summary:

• Analysis of mobile ad impressions from Oct. 3 to Oct. 9 found 56% of Web traffic volume was from the iPhone 5 compared to 44% from the Galaxy S III.
• The iPhone 5 had been on the market 18 days at the end of the study compared to four months for the Galaxy S III.
• 4G browsing speeds helped the iPhone 5 have an advantage.

From the article:

While optimizing online content for both devices is still the smart move for businesses targeting mobile consumers, this comparison emphasizes iPhone users still being the most active – and hence marketable – users of the mobile Web.