As Second Life’s membership soars, businesses and advertisers are beginning to create a presence in the virtual world in hopes of making real-world profits.

With Second Life’s online population nearing one million, more companies are beginning to flock to the service as a way to reach members - and digitally test marketing initiatives that could be applied offline - the New York Times reports. Around 30 companies have now set up shop in the virtual world, according to Philip Rosedale, chief executive of Linden Labs, the San Francisco company that operates Second Life, and corporate interests now own some 5 percent of the virtual world’s real estate.

The site is a relatively inexpensive way for businesses (including at least one ad agency) to reach and interact with consumers, test marketing plans and new product ideas, as well as provide information on current products. Nissan, for example, has set up a virtual racetrack that allows users to “test-drive” its Sentra. Moreover, a presence in the virtual world can translate into real revenue.

That’s because users have their own currency, the Linden Dollar; at current exchange rates, one dollar buys 400 Linden Dollars. An article of virtual clothing, such as a shirt, costs on average about 200 Lindens, or 50 cents. Second Life claims that as much as $500,000 a day in actual dollars changes hands on the site and that amount is growing by up to 15 percent a month.