BOSTON -- Virtual retailers start special holiday promotions on Thanksgiving and extend them through the following Monday.

NewsCenter 5's Rhondella Richardson reported Monday that some online retailers are sweetening the pot with free shipping offers with no minimum purchase.

On the back to work Monday after Thanksgiving, 77 percent of retailers said online sales increased so noticeably last year, that the day is dubbed Black Monday or Cyber Monday.

The store windows set the mood but the reality is, since most workplaces have high-speed Internet, consumers find pointing and clicking a favorite and convenient way of gift giving.

"You don't have to go out. It's being lazy. That's it," one consumer said.

With few exceptions, the most successful online sellers are the most successful stores.

Experts said that online sales would increase by 25 percent this holiday season to hit $18 billion.

About 3.5 million new households began shopping online in 2004, and another 2.5 million are expected to join them, experts said.

According to the National Retail Federation, men shop online at the office more than women. While plane and train tickets corner the online market year round, the big Cyber Monday winners are jewelry and luxury retailers and Web sites selling electronics.