Last year, eBay noticed a new holiday-shopping phenomenon: Traffic spiked the afternoon of Thanksgiving itself. Forget Black Friday or Cyber Monday; as soon as the pie was eaten and the football games were played, commerce was being conducted. Sibling PayPal has now declared post-Thanksgiving dinner as the first shopping spike of the holiday season, starting a tradition dubbed "couch commerce."

Many of those couch purchases are being made on mobile phones. PayPal conducted a national study with Ipsos and found that 46% of those surveyed said they plan to make holiday purchases with a mobile device this year. More than 60% of mobile-influenced buyers will make these purchases at home and 35% of mobile purchases are spontaneous.

Here are three marketer strategies, from Ad Age Insights' fourth-quarter Mobile Marketing report, for mobile commerce.

Optimize for mobile web
More consumers seek out a retail brand via the mobile web than via apps. Google's research shows that the number of queries via mobile rose nearly three times from 2009 to 2011 and continues to expand; mobile search is now 30% of all search activity, which Deep Focus's Ian Shafer identifies as a watershed for mobile commerce. But despite the growth of mobile search, 79% of Google's largest advertisers still did not have a mobile-optimized site.

Have a 'scan and scram' strategy
People walk into stores ready to scan barcodes and check local retail availability and then go buy elsewhere. So what are retailers doing about these scan-and-scram shoppers? Electronics retailer Fry's will match any price a consumer shows a staffer on their phones, while Lowe's is deploying 42,000 iPhones to staffers to assist with scanning for more information and couponing.

In October, Sears Holdings rolled out iPads and iPod Touch devices to almost 450 Sears and Kmart stores. Sales associates will use the devices to help customers check inventory, order products online and access product information and videos. Sears is also offering free Wi-Fi at various locations, so customers can shop at Sears.com and compare prices. Target encourages bar- code scanning; its iPhone and Android applications offer built-in scanner functionality.

Own the couch
Tablets are proving to be the driver of couch commerce, turning the chaos of the web into a more intuitive, consumer-friendly shopping experience. Retailers should put their app efforts here and think more catalog than web: Beautiful images and lifestyle information as it relates to the products work here, as consumers swipe and zoom their way to the purchase. Target has made it possible for tablet users to drag and drop items directly into an online shopping cart from electronic versions of its circular. Also, prepare for the HTML5 future with a tablet-initiated web experience.