It looks like Apple’s iPad is playing a more significant role in online retail than ever expected.

Recently released data in a report by Shopatron show sales conversion rates on the iPad are higher than the rates on both mobile phones and PCs. The findings were compiled using the Shopatron platform, which supports more than 800 brand stores in 35 different industries. As an eCommerce platform, the iPad had an average conversion rate of up to 2.04 percent, faring much better than other mobile devices (iPhone, iPod and Android) which averaged .37 percent. Some retail stores even reported that the iPad conversion rate was nearly twice the rate of PCs.

Based on the numbers, Shopatron believes that shoppers are more likely to place orders from an iPad than a smartphone. The company attributes this idea to the richer shopping experience it believes consumers get from the iPad, as well as its large screen and fast connection speeds. As well, the iPad is closer to the experience of using a personal computer.

So, the numbers from IDC on the growth of tablet computers sold worldwide (led, of course, by the iPad) is definitely welcome news to online retailers. The analyst reports that 17 million tablets were sold in 2010. It predicts 44.6 million tablets will sell this year (with about 40 percent of sales to be in the U.S.) and a whopping 70.8 million units to sell in 2012.

Holiday shopping online may take on a whole new meaning in the car, at the airport, during Thanksgiving Day football commercials …The iPad has come out swinging and already seems to be winning the online retail battle. What’s next?

Tags: Apple’s iPad in online retail, ipad retail, ipad shopping, online retail, smartphone shopping, tablet vs pc, tablet vs smartphone, shopatron