The appeal of online virtual worlds such as Second Life is such that it may trigger an exodus of people seeking to "disappear from reality," an expert on large-scale online games has said.
Will real pubs empty as people head for virtual watering holes?
Virtual worlds have seen huge growth since they became mainstream in the early years of this decade, developing out of Massive Multiplayer Role-Playing Games.
And the online economies in some match those of real world countries.
Their draw is such that they could have a profound effect on some parts of society, Edward Castronova, Associate Professor in the Department of Telecommunications at Indiana University, told BBC World Service's Digital Planet programme.
"My guess is that the impact on the real world really is going to involve folks disappearing from reality in a lot of places where we see them," he said.
Dr Castronova, who has written a book on the subject entitled Exodus To The Virtual World, drew parallels to the 1600s when thousands of people left Britain for a new life in North America.
"That certainly changed North America - and that's usually what we focus on - but it certainly changed the UK as well," he said.
"So what I tried to do in this book is say, 'listen - even if the typical reader doesn't spend any time in virtual worlds, what is going to be the impact on him of people going and doing this?'"
And he predicted that everyone will be involved in a virtual environment within ten years - although the level of that involvement will vary.
He said while some people will be colonists - "the virtual frontier opens up and off they go and disappear" - others will just use virtual worlds to get together with distant family and friends.
But he stressed there will be a group of people that spends all their lives there, and that the big question is the size of this group.
"We forget how many people there are, and we have to ask ourselves, how exciting is the game of life for most people out there?" he said.
Escape and refuge
The appeal, he said, is not for those in a good job, but for those working low-paid, low-skill jobs. "Would you rather be a Starbucks worker or a starship captain?" he asked.
But he also stressed that since virtual worlds are social, he sees increased interaction in them as a step forward.
Virtual worlds allow people to change their appearance from their real look
And he also highlighted the difference between seeing them as an "escape" and as a "refuge."
"If reality is a bad thing, and people are going into virtual worlds to reconnect, the word you would deploy is refuge," he said.
"A father of two spending 90 hours a week in a virtual world because he doesn't like his wife - I would say that's escapism, and it isn't anything you would say is good.
"But if it's a heavy-set girl from a small town who gets victimised just because her body isn't the 'right' kind of body, and she goes online to make friends because she can't get a fair shake in the real world, then I would say the virtual world is more of a refuge."