That has put pressure on brick-and-mortar stores, which can make up to 40 percent of their annual revenue during the two-month holiday shopping season, to compete. That's becoming more difficult: the National Retail Federation, an industry trade group, estimates that overall sales in November and December will rise 4.1 percent this year to $586.1 billion, or about flat with last year's growth. But the online part of that is expected to rise 15 percent to $68.4 billion, according to Forrester Research.As a result, brick-and-mortar retailers are trying everything they can to lure consumers into stores by making shopping as easy as possible. They tested the earlier hours last year, but this year more stores decided to open their doors on Thanksgiving. In addition to expanding their hours, many also are offering free layaways and shipping, matching the cheaper prices of online rivals and updating their mobile shopping apps with more information. "Every retailer wants to beat everyone else," said C. Britt Beemer, chairman of America's Research Group, a research firm based in Charleston, S.C. "Shoppers love it." Hardcore holiday shoppers took advantage of the earlier hours. There were 11 shoppers in a four-tent encampment outside a Best Buy store near Ann Arbor, Mich., in the afternoon on Thanksgiving. The purpose of their wait? A $179 40-inch Toshiba LCD television is worth missing Thanksgiving dinner at home. Jackie Berg, 26, of Ann Arbor, arrived first with her stepson and a friend Wednesday afternoon, seeking three of the televisions. The deal makes the TVs $240 less than their normal price, so Berg says that she'll save more than $700. It's her first time camping out for the specials, and she's not sure she will do it again. Relatives will bring her some holiday dinner, but she'll miss eating her dad's stuffing right as he cooks it.