Customers may shop online while in store

— -- A tablet-toting Macy's salesperson ordering a diamond necklace with a Macys.com app — for a customer standing in a Macy's store.

Walmart shoppers pulling up maps of their neighborhood store online — so they can better navigate the aisles to grab the best in-store Black Friday deals.

Toy-seeking parents ordering Lets Rock Elmo from Toysrus.com — yet heading to the physical store to pick the gift up.

The boundaries separating online and in-store shopping are fast dissolving.

Consumers are increasingly doing online research before they head out for holiday gifts. When they get to stores, they're pulling out smartphones and tablets to compare prices and read reviews.

For their part, retailers are both pushing people to their websites — so they can cut back on in-store stock expenses — and using Web-based initiatives, such as free Wi-Fi, to keep shoppers in their stores.

Online and offline experimentation will be omnipresent this holiday season, as retailers and consumers both try to figure out the most effective way to shop.

"One of our major strategies is to let (multiple shopping channels) blend together," says Martine Reardon, Macy's executive vice president of marketing and advertising. "My challenge is to give shoppers that great experience from every channel."

There is much at stake for the retailer who can't figure out how to integrate online and in-store shopping. Those who have slow-to-load websites, don't offer helpful apps or aren't optimized for digital and mobile devices could lose customers this season, experts say.

Underscoring the importance of retail websites: Thanksgiving Day online sales were up by about 20% over 2010 by noon PT, according to the Web analytics company IBM Coremetrics. Also, shoppers were using mobile devices more often to visit — but not necessarily buy from — a retailer's website Thursday, Coremetrics said. The share of consumers using mobile devices to visit a store's site was up from 4% to 16%, Coremetrics said. But the percentage using their mobile devices to make a purchase was unchanged at 10%.

Many retailers are dawdling, some even stumbling, when it comes to courting increasingly tech-savvy shoppers, based on new data from Web analytics firm Compuware Gomez.

Less than half of the top 30 retailers have iPad apps, and none have websites that are specifically optimized for the iPad. Three-fourths of the top U.S. retailers are not meeting shoppers' expectations that mobile Web pages should load in five seconds or less, according to Compuware.

"Retailers don't appear to be investing enough to capture that market," says Steve Tack, Compuware's chief technology officer for application and Web performance.

Dissatisfied consumers could quickly move on to competitors at a time digital sales are one of the few bright spots in holiday retailing, Tack says.

November and December online sales (excluding travel) are expected to grow 16.8% from last year to $46.7 billion, research company eMarketer says.

Yet, overall holiday spending, including in-store purchases, is expected to be tepid, rising 2.5% to 3.5% from last year, according to industry predictions tracked by eMarketer.

Technology shifts behavior