Holiday business was strong, and signs abound that despite some glitches, shopping on the Web is become more accepted among consumers.

Amazon.com, the bellwether of online retailers, said on Friday that it set a record with more than 2.1 million items ordered in one day during the shopping season.

The Seattle company also reported it shipped more than 1 million packages on its peak shipping day and sold more than 70,000 gift certificates on Christmas Eve.

BizRate, a California online shopping research firm, reported online retail sales for Dec. 25 were $83.64 million, tailing off from the $200.77 million recorded on Dec. 22, which was the last day to order for Christmas Eve delivery.

By the time the Christmas retail season was over, online shoppers had spent $8.6 billion, 24 percent higher than last year.

Furthermore, nearly half of online retailers have seen holiday sales increase more than 35 percent over last year, according to a study released by Shop.org, an association for online retailers.

However, the performance of the major online shopping sites themselves left something to be desired — mainly speed.

They displayed inconsistent and slow performance for holiday shoppers attempting to buy gifts on the Internet from Dec. 15-21, basically unimproved from previous weeks, according to Keynote Systems, a San Mateo, Calif., firm that measures Web performance.

The overall average response time for completing a transaction, according to Keynote, was "a mediocre 14.77 seconds."

It's also unclear how U.S. Internet retail sales will measure against the rosy forecasts made early in the season. Forrester Research, a Boston firm that studies high-tech industries, predicted online holiday sales would rise 42 percent; Jupiter Research in New York City forecast that consumers would spend 21 percent more money online.

Since Forrester, Jupiter and BizRate use slightly different methodology and shopping periods, a straight comparison doesn't reveal much. A clearer picture will emerge when Forrester and Jupiter tally up their final results later.

Free shipping once more was the top factor drawing shoppers to the Internet, BizRate spokeswoman Helen Malani said.

The average shipping charge dropped 19 percent from last year, to $9.91, despite an increase in online retailers offering express shipping for orders made in the final week.

Even though revenue went up, the average purchase amount dropped some $32 from 2002, to $103 this year, Malani said.

Computers and consumer electronics continued to be top sellers, as they have done historically when mainly men shopped on the Web, according to BizRate.