TigerDirect is logging a 63% increase in mobile conversions since it launched a new mobile site last September.

TigerDirect, which sells computer goods, had an old mobile site, which was built by Velocitude, now a subsidiary of Akamai Technologies, Inc., but it  was not generating much mobile sales, says Lonny Paul, vice president of marketing and strategic initiatives at Systemax, Inc., No. 25 in the Internet Retailer Top 500 Guide parent company of TigerDirect, CompUSA and Circuit City. For example, the site only accepted Google Checkout , he says. So he chose a new e-commerce technology vendor, Branding Brand, to revamp the mobile site.

Systemax chose Branding Brand to build the site because the company could take content from the e-commerce site to build the m-commerce site quickly and with no up-front fees, Paul says. “Within six weeks, as promised, we had a fully functional site,” he says.

Shortly after launching, Paul was surprised to receive a phone call from Branding Brand telling him they’d noticed a problem with shopping cart conversions on the mobile site the week before—but they’d already fixed it. “They did it on their own,” he says. “While I was worrying about all those things, they were really on top of it almost as much as I was.”

Branding Brand re-platformed the TigerDirect mobile site so that it ran much faster, with more functions and is better optimized for mobile, says Branding Brand CEO Christopher Mason. The new mobile site now lets consumers pay using PayPal Express Checkout for faster purchasing and features redesigned product images and “add to cart” buttons. Branding Brand also runs usability tests and tests performance daily, tweaking as needed, he says.

Consumers using Android devices account for half of traffic to the mobile site, with iPhone users accounting for 41%. But the retailer says iPhone shoppers convert 74% more often than those using Android devices.