Holiday shoppers buy early, often, online By Nivedita Bhattacharjee and Brad Dorfman CHICAGO (Reuters) - U.S. shoppers went to stores earlier and bought online more than before this Thanksgiving weekend, giving retailers a strong start to the holiday shopping season, data showed on Sunday. Likely beneficiaries included retailers that have done a better job of combining their physical stores with their online and mobile channels into a seamless shopping experience, analysts said, mentioning the likes of Wal-Mart Stores Inc and Macy's Inc. "The more you can make a shopper shop multiple channels, they are at least twice as likely to be a loyal shopper and spend tons of money," Patty Edwards, chief investment officer at Trutina Financial, said. Total spending for the weekend rose to $59.1 billion from $52.4 billion last year, according to a survey from the National Retail Federation. An estimated 139.4 million adults visited U.S. stores and websites from Thanksgiving through Sunday, up from 131 million last year, the survey, conducted for the industry trade group by BIGinsight, said. ComScore Chairman Gian Fulgoni said "Cyber Monday" online sales may reach $1.5 billion this year. That would be up 20 percent from the corresponding day last year, though slower year-over-year growth than Thanksgiving and Black Friday. Amazon.com was the most-visited retail website on Black Friday, and it posted the highest year-over-year visitor growth rate among the top five retailers. Wal-Mart's website was second, followed by sites run by Best Buy Co, Target Corp and Apple Inc, comScore said. While the start appeared good, whether they can sustain the initial burst through the holiday season is the key for retailers, which can book a third of their annual sales and 40 to 50 percent of profits for the year in November and December. The impact on the U.S. economy is also sizeable as consumer spending accounts for about 70 percent of all economic activity. There are two extra days between Thanksgiving and Christmas this year and one more full weekend, so the opportunity for a lull between the holidays is greater. "A big Black Friday, it's hard to read too much into that for the rest of the season," Scott Tuhy, vice president at Moody's Investors Service, said. Staying open on Thanksgiving became more widespread this year as retailers such as Target, Sears Holdings Corp and Toys R Us Inc joined in, while others including Wal-Mart and Gap Inc either extended their operating hours or had more stores doing business. "When you see strong sales on Thursday and Friday, you know it is going to come from later in the weekend or later in the season," Steve Krenzer, chief executive of shopping comparison website PriceGrabber, said. The National Retail Federation still expects sales in November and December to rise 4.1 percent this year, below last year's 5.6 percent increase. Reporting by Nivedita Bhattacharjee and Brad Dorfman in Chicago; Additional reporting by Alistair Barr in San Francisco and Martinne Geller in New York; Editing by Dale Hudson