Many shoppers (us included) will be skipping the long lines this Black Friday and heading online instead.

This year, online shoppers are expected to spend $1.6 billion on Black Friday alone, up 17 percent from last year, according to a holiday shopping forecast published by Adobe. That's on top of all the early shopping they'll do on Thanksgiving, which is expected to reach $1.1 billion this year, up 21 percent from 2012.

Those are impressive numbers, especially given that shoppers aren't planning to spend more overall this holiday. They're simply spending more online instead.

With so many shoppers going online on Thanksgiving and Black Friday, one might wonder if there's any need for Cyber Monday anymore. (The initiative was spearheaded eight years ago by Shop.org as online retailers' own version of Black Friday -- a day when e-commerce sites would lure shoppers online with discounts, free shipping and other incentives.) But it's still going strong. In fact, with an expected $2.27 billion in sales, it's sure to be the biggest online shopping day of the whole year once again. FedEx, too, is predicting a bigger Cyber Monday than ever, with an estimated 11 percent increase in shipments.

Online retailers hoping to cash in between Thanksgiving and Cyber Monday better have their mobile sites at the ready. Adobe estimates that more than 20% of online sales over the period will take place on mobile-optimized sites, up nearly 50% from last year. Many shoppers will also be using their phones to check online for lower prices.

One place sales won't be coming from is social media. Per Adobe, only two percent of sales will come through sites like Facebook, Twitter, YouTube and Pinterest. That being said, those platforms still have a role in the "purchasing journey": In Adobe's survey of 400 shoppers, 36% said they plan to turn to social media to help make purchasing decisions.

The prospects for Black Friday and Cyber Monday may be rosy, but it's going to be a tough season for retailers overall. Thanksgiving is late this year, meaning that shoppers will only have 27 days to shop before Christmas. It could cost them as much as $1.5 billion in potential sales, Adobe says -- and it means much better discounts for shoppers like us.