Holiday shoppers took advantage of online deals on Thanksgiving and Black Friday, the day after Thanksgiving, ringing up $2.8 billion in sales for retailers, according to research firm comScore Inc.

Online sales on Thanksgiving topped $1.1 billion, a 9% increase from $1 billion in 2014.Black Friday sales of $1.7 billion were 10% higher than $1.5 billion in 2014.

“This is also the second straight year that Thanksgiving has established itself as one of the more important online buying days, while Black Friday continues to gain in importance online with each passing year,” said Gian Fulgoni, comScore chairman emeritus, in a press release.

Retail sales in stores were estimated by research firm ShopperTrak at $12.1 billion for both Thanksgiving and Black Friday. That is a decrease from the 2014 figure of $12.3 billion.

“This year, we saw Black Friday ads emerge before Halloween, as retailers aimed to get at the shopper’s wallet early,” said Kevin Kearns, ShopperTrak chief revenue officer, in a press release. “And from our data, we saw greater retail sales generated prior to the Black Friday weekend, which is a result of retailers successfully elongating the holiday season.

Digging deeper into consumer e-commerce shopping patterns over the long holiday weekend, mobile traffic accounted for 57.2% of all online traffic, a 15.2% increase from 2014, says IBM Corp.’s “Black Friday Report 2015.” Mobile sales accounted for 36.2% of all online sales.

Smart phones were the device of choice for many consumers, accounting for 44.7% of all online traffic, a significantly higher figure than the 12.5% for tablets.

With respect to actual online sales, 20.6% were made with smart phones, IBM says, compared with 15.5% for tablets.

As for Cyber Monday, IBM forecasts online sales will grow by more than 18% compared to 2014. ComScore said e-commerce spending on the 2014 Cyber Monday was $2 billion.