The amount of money spent shopping online during the holiday season increased this year compared with last, say two recent reports, another sign of the Internet's continuing permeation of American life.

SpendingPulse, a report from MasterCard, pegged the year-over-year rise at 15.4 percent. The report, released this week and covering the period from October 31 to December 24, looks at sales in the MasterCard payment network and combines those figures with survey-derived estimates of non-credit-card purchases.

According to the report, apparel sales led the field among e-commerce categories, a sign, perhaps, that shoppers are becoming more comfortable with buying clothing sight unseen. Electronics also made a showing, and jewelry managed to log an increase as well.

In general, the results show that the Web seems to be continuing on its way to becoming as American as apple pie--or the shopping mall. Though according to various sources online sales still make up only 10 percent of all purchases, that seems likely to change.

"Today e-commerce accounts for a much larger share of overall retail sales compared to a few years ago," Michael McNamara, vice president for MasterCard Advisors SpendingPulse, said in a statement. "And during this holiday season, it registered double-digit growth for six out of seven weeks."

The SpendingPulse report said that this year, the Monday after Thanksgiving saw $999.3 million in e-commerce receipts, a 25.3 percent increase over that same day last year. And six days in this year's holiday shopping season saw online sales of more than $1 billion, compared with three days in 2009.

ComScore served up its own batch of figures this week, with its report covering November 1 through December 20 and based on surveys of consumers. The analytics company reported a 12 percent increase in e-commerce spending during that time frame versus the same frame last year.

In a statement, ComScore Chairman Gian Fulgoni said a 17 percent year-over-year rise in e-commerce receipts during the last weekend before Christmas "capped the heaviest online spending week of all time at $5.5 billion."

The company also singled out other significant dates:

"We're watching online retail, and increasingly social media and mobile, become the growth engines for retailers everywhere, as consumers embrace online shopping not only for its ease and convenience, but as a primary means of researching goods and services," John Squire, Coremetrics' chief strategy officer, said in a statement at the time.