More consumers let their smartphones do the shopping –

When Te-kai Shu got to the register at Best Buy on Black Friday, he didn’t pull out a rewards card or coupon to rack up extra savings.

“I whipped out my smartphone … to make sure (the cashier) credited my purchase to my Reward Zone account,” say Shu, 29, of Bristol, Tenn.

Shu is part of a growing group of consumers who look to their smartphones — Internet-enabled mobile phones — to save money and stay informed when buying. Nearly six in 10 mobile users say they’ll be using their phones for holiday shopping, and retailers are falling all over themselves to offer applications and mobile websites to meet the demand. With smartphones, shoppers can compare prices, store loyalty and gift cards, make wish lists and get discounts at their favorite stores.

But retailers also risk alienating customers if the apps and mobile websites fail to deliver. More than half of customers surveyed say they won’t return to a mobile site if they’ve had a poor experience, according to a study by Gomez, Compuware‘s unit that studies website performance.

And performance expectations are high: Nearly 60% of people anticipate mobile sites will run as smoothly as or better than sites they visit on their computers, the Gomez study showed. Meeting the challenge has been difficult. Consumers ranked the performance of mobile sites of the Thanksgiving holiday weekend’s 15 largest retailers as “tolerable,” compared with the retail websites overall.

How interesting…