New York ? Shoppers logged onto the Internet in large numbers during an unusually early and robust start to the holiday season.

Typically, the online holiday season officially starts on the Monday after Thanksgiving, when many people start shopping from the workplace computer. But this year, many online retailers saw sales soar on Thanksgiving Day itself.

That shows how consumers are increasingly using the Internet as an information tool — scouring for deals and then purchasing as much as they can online before heading to the malls for those early bird specials on Friday. The change in shopping patterns also reflects how millions of homes have converted to high-speed Internet connections, making it easier to shop from home, analysts said.

In fact, Sears, Roebuck and Co. for the first time gave online customers early access to Friday’s specials, allowing them to order on the Web on Thanksgiving Day — and then pick up the merchandise in stores.

“They’re home and they’re getting ready for Friday,” said Greg Ahearn, vice president of marketing for Toysrus.com, which offered special deals on toys on Thanksgiving Day.

BizRate.com, a comparison shopping site that also tracks sales at 2,000 e-commerce sites, reported that sales increased 30 percent on Thanksgiving Day to $197 million, compared with $151 million a year ago.

For the four-day weekend that ended Sunday, BizRate.com reported that sales for the 2,000 sites it tracks totaled $820 million, compared with $735 million during the year-ago period.

BizRate.com said Monday remained the busiest day of the holiday weekend, with sales reaching $256 million, up 26 percent from $203 million a year ago.

Forrester Research estimated that online sales from Thanksgiving weekend to Christmas will increase 42 percent over a year ago to $12.2 billion.