American consumers bought into e-commerce in a big way during 2006, as online retail spending eclipsed $100 billion for the first time.

Spending at U.S. online non-travel sites reached $102.1 billion, marking a 24-percent increase versus 2005, according to comScore Networks.

Much of that growth is due to a record-breaking holiday season that began with a Black Friday boom and a huge Cyber Monday.

Twelve days during November and December surpassed the $600 million mark in 2006. In comparison, just six days in 2005 reached $500 million in online sales.

And many of those big days came later than ever before.

On Monday Dec. 11, consumers set a single-day record for online spending with $661 million. But two days later, that record was broken as shoppers spent $667 million online. American shoppers during the following two days spent 33 percent and 38 percent more online than they did the same two years before.

By the end of the season, holiday e-commerce accounted for $24.6 billion, up 26 percent versus last year.