Measurement firm Media Metrix also reports that it's not just book, music, and video sites that are being visited as online buying expands to other categories such as apparel and department store merchandise.
"Significant numbers of people are moving from site to site, category to category," said Robert Ivins, Media Metrix senior vice president. "There is a huge class of shoppers who are ready, willing, and able to make online purchases."
Bloomberg also reports new estimates from Ziff-Davis that online holiday sales will reach $3.5 billion this year. Ziff's Internet unit said twice as many U.S. adults are shopping on the Net today compared to a year ago.
Ivins of Media Metrix thinks convenience is driving shoppers to use Web storefronts. He also cites the arrival of brand-name retailers and direct marketers and far more Internet users.
Ziff said the number of consumers who either bought or researched holiday gifts between October 1 and December 16 increased to 19.8 million from 8.3 million in 1997. About 65 million adults used the World Wide Web in the past three months.
Ziff said online shoppers will buy an average of $457 worth of goods this year, with the most popular gifts being books, followed by compact discs, clothing, consumer electronics, computer hardware, and software.
Of the 19.8 million adults who used the Web for shopping, Ziff said 7.7 million purchased gifts online using a credit card. About 3.6 million people mailed or faxed their orders, while 12 million went to a store to make a purchase. Six million adults said they phoned in the order.
Media Metrix said the "cross visitation" statistics--shoppers who visit different kinds of Web storefronts--will help retailers determine patterns and hone their marketing efforts.
The hottest categories in the most recent week were relatively modest increases in traffic to apparel stores [up 11 percent] and books/music/movie [plus 6 percent]. Toy sites, which showed the biggest increases in the first week of December, declined 14 percent. Department stores were virtually unchanged.
More men are shopping online in the latest week, with the gender mix now split evenly between males than females. One wag attributes that to men's last-minute shopping habits.
Bloomberg contributed to this report.