NEW YORK – Shoppers who skipped the crowds on Black Friday gave online merchants a 16 percent spike in revenue, according to data released Saturday. That’s spurring optimism for spending the rest of the season.

That increase came partly from shoppers who spent more per online purchase during the traditional opening day of the holiday shopping season, according to the Web research company Coremetrics. The average order rose to $190.80. That’s a 12 percent increase over $170.19 on the same day last year.

The increase adds to a 33 percent online spending spike on Thanksgiving Day, and signs of bigger-than-expected crowds in stores.

“The season’s off to a great start,” said John Squire, Coremetrics vice president of strategy. “It really shows really strong consumer sentiment for buying and for going online.”

Lots of shoppers made the night after Thanksgiving an all-nighter. “Even at 1 a.m. Pacific, there was still very strong buying across the U.S.,” Squire said.

Shopping on smart phones remained a small, though growing, piece of the pie. Coremetrics said about 5.6 percent of people logged onto a retailer’s website using a mobile device. That compares with less than 1 percent on last year’s Black Friday, Squire said.

More dollars have shifted to online shopping over the years, but it’s still a relatively small share of all holiday spending — between 8 and 10 percent.

But many shoppers have become converted to the comfort and convenience of browsing the Web for gifts.

Kelly Hager, 30, of Baltimore is shopping exclusively online for the fourth year in a row.

“It’s nice to not have to fight for a parking spot and deal with 3 billion people who are all trying to get the same thing I’m trying to get,” she said. Hager used to work at a mall, so she’s seen Black Friday from both sides.

Those who did fight the crowds had retailers feeling bullish about the prospects for the rest of the holiday season. Broad discounts spurred long lines.

Retailers and analysts were also encouraged that people seemed to be buying more items for themselves, a sign they’re feeling confident enough to spend more money overall.