More than 12 percent of traffic to retailers’ and other marketers’ Web sites now come from mobile devices, according to a new report from Walker Sands Communications.

The Walker Sands Quarterly Web Traffic report found that the amount of traffic coming from mobile in the fourth quarter of 2011 increased 102 percent compared with the same period a year ago. IPhone saw a 17 percent decline in terms of its share of the market while Android rose 19 percent.

“Mobile has now reached the point where it absolutely should not be ignored,” said Daniel LaLoggia, direct marketing manager at Walker Sands, Chicago.”On average, more than 1 in every 10 visits comes from a mobile device.

If your site is not designed to provide a user-friendly visitor experience, you could lose out on valuable conversions,” he said.

“Despite iOS’s presumed dominance in the marketplace with the iPhone and iPad, Android’s market share is actually on par with iOS. Retailers and marketers that only focus on Apple devices are missing out on converting a large portion of their mobile visitors.”

Android’s growing presence
In the fourth quarter of 2010, iPhone had a 48 percent share of mobile traffic to Web sites but that dropped to 31 percent in the fourth quarter of 2011.

IPad’s share grew 6 percent from a 10 percent share to a 16 percent share.

Android’s share grew from 27 percent to 46 percent during the same period.

This means that if iPhone’s and iPad’s share are combined, iOS is running neck-and-neck with Android.

“The most surprising finding was seeing iPhone’s percent of total mobile traffic fall 17 percent from Q4 2010 to Q4 2011,” Mr. LaLoggia said. “This does not mean there are fewer iPhones out there but rather, as the market expands, Android has been able to grow their presence in a way that Apple has not due to Android’s lower price points and the variety of handsets available.”

BlackBerry’s share of Web site traffic dropped 6 percent over the year for a total of a 4 percent share.

Mobile traffic rose steadily throughout last year, starting out at 6.93 percent in the first quarter and rising to 12.59 percent in the fourth quarter.

Mobile conversions
Some sites fared better than others in terms of the amount of traffic coming from mobile.  

The largest year-over-year increase for an individual site was a 252 percent increase in mobile traffic. The site with the largest percentage of mobile traffic had 24.93 percent of all traffic coming from mobile in the fourth quarter.

However, the report also found that one site lost 10 percent of its mobile traffic as a result of a shift in strategy, a Web site redesign and an overall reduction in search traffic. The site with the lowest percentage of mobile traffic had 4.72 percent of all traffic come from mobile in the fourth quarter.

“The first and foremost action retailers should do to take advantage of this growth in mobile traffic is to find out if their mobile traffic is converting,” Mr. LaLoggia said. “If the conversion rate is significantly lower for mobile traffic than the rest of the site, mobile conversions can be improved through a brand-customized mobile site, mobile friendly version of an existing site, or by streamlining the e-checkout or conversion forms for mobile users so they are more likely to finish a transaction.”

Final Take
Chantal Tode is associate editor on Mobile Commerce Daily, New York