DETROIT (CBS Detroit) Target and Walmart are among retailers pushing the Black Friday envelope by opening shortly after the Thanksgiving dinner dishes are cleared.

But as many know, you can shop the biggest Black Friday sales without leaving the easy chair or buckling your post-dinner belt.

If you plan to shop Black Friday deals online, you won’t be alone: 71 percent of Americans believe the best deals are online, and more Michigan residents than ever are expected to start their holiday shopping on Black Friday. Get a complete rundown of all the Black Friday ad deals HERE.

ComScore’s data shows that online spending on Black Friday 2011 grew 26 percent from Black Friday 2010 to $816 million, making it the heaviest online spending day to date in 2011.

And ComScore is predicting an even merrier holiday season for U.S. web retailers in 2012. The web measurement firm predicts online sales will increase 15 to 18 percent this holiday shopping season compared with 2011.

One factor helping web sales this year is that there are two extra shopping days between Thanksgiving Day and Christmas, comScore says.

For this holiday season, social media will play a bigger role than ever in purchasing decisions, said Andrew Lipsman, vice president of industry analysis for comScore.

“Pinterest has more than 20 million more monthly visitors than it did going into last holiday season,” Lipsman said about the social network where participants “pin” their favorite items and share them with fellow users.

Online holiday sales on Cyber Monday have swelled 105 percent over the past five years, while web sales over the entire holiday shopping season have grown 51 percent since 2006, comScore says. Web sales on Thanksgiving Day, meanwhile, have grown 128 percent over the same time period.