With all the iPhone leading the buzz about smartphone growth, it’s disheartening to learn that the Apple phone is the worst smartphone for mobile advertising. That is, at least according to a new report about mobile ad clickthrough rates by online ad network Chitika.

But with the right advertising, smartphone users, and yes, even iPhone users, are receptive to mobile advertising. The important thing is getting the message right, and relevant in today’s mobile real-time, real-location, really-useful digital society.

Of the five major smartphone operating systems – Google’s Android, Apple’s iPhone, Microsoft’s Windows CE, Palm OS, and Research In Motion’s BlackBerry – iPhone ranked the worst for clickthrough rate at just 0.30%. iPhone also accounted for the bulk of mobile hits, at 66%.

Chitika’s data is based on monitoring 92 million impressions in September, the Chitika study shows that mobile users are approximately half as likely to click on an advertisement as non-mobile users. Of the 92 million impressions cited in the study, approximately 1.3 million (1.5%) came from mobile browsing. While non-mobile held steady with a 0.83% clickthrough rate, mobile as a whole pulled a mere 0.48% – just over half of the average.

However, research firm Compete Inc. released a recent report that says iPhone users are open to receiving targeted messages via their iPhones are welcome, as long as they’re relevant in real-time to the user. They found that 30 percent of all smartphone owners are comfortable or very comfortable receiving targeted marketing on their device.

“Of those users, nearly half are receptive to location-based offers at restaurants — or other offers to pursue at their leisure — and 45 percent said they would use mobile grocery coupons through targeted marketing offers,” Danielle Nohe, director of telecommunications and media at Compete told MobileMarketer.