As online sellers kick off the coming week with one of their biggest sales days of the year — Cyber Monday — its brick-and-mortar counterpart — Black Friday — offers some encouraging signs: Consumer are shopping more enthusiastically in stores and online before the big days.

Online payment service Paypal said Friday that it saw a 25 percent increase in payment volume on Thanksgiving this year versus last year. PayPal also noted a 297 percent jump in mobile payment volume on Thanksgiving from last year.

The National Retail Federation estimates that Cyber Monday deals will be much more aggressive this year.

The group said 88 percent of retailers will have a special promotion for Cyber Monday this year, up from 72 percent in 2007.

But since Monday is a working day, many consumers will try to sneak in some shopping while at work.

According to the federation, 54.5 percent of workers with Internet access, or 70.1 million people, will shop for holiday gifts from the office, with most being men and young adults.

ComScore, a digital marketplace research firm, expects online sales for the 2010 holiday season to reach $32.4 billion,  an 11 percent increase  for November-December from a year earlier.

Sales for that two-month period were  4 percent more than in 2008, the firm said.

“The beginning of the online holiday shopping season has gotten off to an extremely positive start, outperforming our earlier expectations,” ComScore chairman Gian Fulgoni said in a statement.

“Despite continued high unemployment rates and other economic concerns, consumers seem to be more willing to open up their wallets,” he said, adding that deep sales have spurred much of that momentum.