2007 was another boom year for the Internet in the United Kingdom. Almost 37 million people went online in an average month—that’s over 60% of the population.

This year looks like more of the same, and by 2012 eMarketer estimates that the Internet will reach roughly 70% of all UK residents.

”Britain has one of the most experienced and active online populations in the world,” says Karin von Abrams, eMarketer Senior Analyst and author of the new report, UK Internet: Users and Usage, “Confidence in e-commerce is high.”

In fact, the UK will account for at least 40% of 2008 online sales in Western Europe. This proportion will decline slightly as e-commerce becomes better established elsewhere in the region, but the UK will still represent the greatest single share of the European market in 2011.

“A long tradition of catalog and mail-order shopping has contributed to the practice of online buying in the UK,” says Ms. von Abrams.

In addition, most e-buyers in the UK have generally had satisfactory experiences with online commerce.

“Merchants have been careful to establish excellent security for transactions and reliable delivery services,” says Ms. von Abrams. “And online prices are very competitive, particularly for books, travel tickets and items bought at auction sites.”

Not surprisingly, the average spend per buyer has been rising steadily, and eMarketer estimates the number will approach a healthy £2,000 ($3,800) in 2008.

“The UK’s Internet shoppers favor the same kinds of sites as online buyers in the US and other European countries,” says Ms. von Abrams. “But they must be big readers—both Amazon UK and Amazon.com were in a recent list of top 10 most-visited shopping sites.”

See where this bellwether economy is heading online. Download the new eMarketer report, UK Internet: Users and Usage, today.