Many new buyers are 35 years and older as the user base trends toward a more balanced age and gender split. However, the economic gap continues to widen. Smartphone owners have always skewed toward higher household incomes-how else could they afford smartphones?

The Android and iPhone are the two most popular smartphones by far, according to OPA: 46 percent of smartphone respondents have an Android phone, and 35 percent have an iPhone. Both platforms rose nearly 10 percent from last year. BlackBerry holds third place with 16 percent, a decline of nearly 10 percent.

One of the more interesting findings stems from the differences between the Android and iPhone: iPhone users are more positive about smartphone advertising than their Android counterparts. That is, consistently more iPhone owners think ads are eye-catching, relevant, hard to ignore, and motivates them to research and buy, according to the OPA survey.

Tech analyst Rob Enderle says that despite this survey's results, the iPhone is not necessarily a better advertising platform than Android and that advertisers are not likely to pick one platform over the other. He says the study suggests a confidence interval between 5 percent and 10 percent.

"This places Android and iOS as equal peers and, given these ads are typically delivered inside apps or through the Web, it is likely advertisers will treat both dominant platforms equally," Enderle says.