Google will shut down Lively, its browser-based virtual world environment, by the end of December.

Launched in July, Lively is Google's alternative to Second Life and other virtual world environments.

But the site did not measure up. Lively.com currently only has about 10,000 unique users who use the site at least once a week, according to an e-mail Thursday from a Google spokeswoman.

"We set Lively tough targets, and it did not achieve them," she added.

Google said it launched Lively because it wanted users to be able to interact with their friends and express themselves online in new ways.

A posting on the company's blog said that after four and a half months on the Lively project, resources would be better spent focusing on its core search, advertising and applications businesses.

"We've also always accepted that when you take these kinds of risks not every bet is going to pay off," the posting added.

Google employees working on the project will move to other teams, according to the blog.

Lively users have been asked by Google to capture their work by taking videos and screenshots of their rooms. Rooms and avatars on the site will not be available after Dec. 31.

Nonetheless, Google believes it benefited from the project. "Lively did teach us about what our users like and what they don't," the spokeswoman said. "We learned people want to be social in many places on the Web, and we learned that users appreciate the ability to meet new people and share content with friends."

These are important lessons for future product development, she added.