The iPhone delivered click-through rates on ads 35% better than the average compared to gaming devices and rival smartphones like the BlackBerry and Android-powered handsets, according to a new study by mobile ad network Quattro Wireless.

In addition to device type, the research -- based on the 4 billion ads per month served on the Quattro network in the second quarter -- also looked at response rates across criteria including ad type and industry sector and brands. The study used indices in which 100 is the average and performance is judged below or above that figure.

So the iPhone had an index of 135, followed by gaming devices at 105. Other phones had below-average click-through rates, with Palm devices at 79, Android phones at 66, and BlackBerry at 62.

But as the BlackBerry improves browsing and more Android devices launch, Quattro expects an increase in its overall CTR.

The iPhone and iPod touch also accounted for the most ad impressions on the Quattro network in the second quarter, trailed by the Samsung Messager, T-Mobile Sidekick and BlackBerry Curve 8330.

When it comes to ad types, the company found that animated ads had the highest impact, with an index of 171 and a 63 percentage-point advantage over standard banners (108). Expanding ads had average click-through rates (98), "but as they are really mini-websites, the audience does not need to click through the ad to another site to engage with the brand," according to Quattro. Text ads were the least effective, generating rates 28% below average.

Sizing up ad performance by industry, consumer packaged goods, autos, finance and entertainment were the categories posting the highest click-through rates. (CPG indexed north of 200.) That's mainly because they often use direct-marketing techniques on mobile phones, like offering coupons or recipes, to drive traffic to landing pages.

Auto, finance and CPG also are typically paying much higher CPMs than average due to higher levels of targeting and the use of rich media to lure consumers.

Finance, telecom and entertainment marketers are most likely to buy on a CPM basis, splitting spending between banner and text ads. Quattro expects the proportion of animated and rich media placements to grow in tandem with the spread of smartphones.

But Quattro conceded that the line between direct-response and brand advertising is more blurred than in other media. "Some advertisers are running brand campaigns with highly targeted media and rich media executions, which they augment with CPC (cost-per-click) campaigns to gain efficient reach and learnings from direct-focused messaging."

Because mobile Web browsing and gaming skew young, the medium has been an especially attractive platform for entertainment marketers. Quattro's report spotlighted specific entertainment-related campaigns on its network, including an effort promoting Green Day's "21st Century Breakdown" album that ran ads in three countries linking directly to their iTunes page.

It also pointed to launch campaigns for new movies and TV show seasons including ads for the FX series "Rescue Me" that it says generated high levels of engagement by using video clips of the show in expanding ads on the iPhone, iPod Touch and Android devices.