A new report from the content marketing platform BrightEdge indicates that while traffic on the mobile web continues to ramp up, monetization remains elusive. The company found that traffic from mobile phones in the first half of 2013 was up more than 125 percent over the same period last year; desktop traffic grew only 12 percent during the period.

But while tablet ad conversion rates were nearly identical to desktop conversion rates, mobile phone users converted only one-third as often. In a press release touting the report, BrightEdge exec Brad Mattick said several factors were to blame for mobile’s lagging conversion rates, including deceptive ads and an inability to accurately gauge the effectiveness of mobile marketing campaigns.

Mattick also blamed some marketers and publishers for not designing content specifically for mobile, urging them to follow Google’s guidelines for creating smartphone sites. Google encourages publishers to embrace responsive design, which is an effective strategy for building a single site that conforms well to multiple hardware platforms. But while responsive design is a good solution for some media outlets and other publishers, it generally can’t engage users as effectively as a dedicated mobile site that is designed from the ground up for the small screen and — just as importantly — is created to address the fact that people often want different things from the mobile web than from the PC web. And that kind of engagement is sure to lead to higher conversion rates.