The holiday season is less and less important for retailers, as more shopping moves online, according to a new study. Coresight Research said Tuesday it’s calling for a 4% increase in U.S. retail sales this November and December, which isn’t as robust as some estimates already out there. For comparison, Coresight said total retail sales over the past three months climbed 4.1%, from the same three-month period a year ago. The firm called out “the ongoing trend of holiday shopping becoming less important to key retailers.” It said the holiday season accounted for almost 24% of all retailers’ sales in the late 1990s, but is closer to 21% today. And Coresight is expecting that percentage to continue to shrink. Read more at CNBC.