Joseph Olin, president of the Academy of Interactive Arts and Sciences, notes that in-game economies have appeal to both users and game makers. "Most people playing in these persistent world environments are building their character. In E.V.E., third party brokers trade currencies in virtual worlds. Nexon has shown across all of their games that if you have the right balance of in-game economies and real world value, consumers are happy to spend some money there."

Is some of the crossover between online and offline barter on the up-and-up? The translation isn't cut-and-dried--as the case of Blizzard's War of Warcraft showed. There, the company successfully blocked people who were cheating by paying someone money in the real world to up their character's level for them in the virtual world.

In another sense, relative values have changed--and so have what people are willing to pay for in small doses. "Who would have thought ringtones, wallpaper screensavers, and non-game mobile entertainment would be a $250 million business?" muses Olin on the success of mobile carriers promoting such services.

The bottom line in the trend towards micropayments is less about the user experience and more about the game makers' bottom line, though. Olin says, "Interactive entertainment companies are looking for ways to monetize their investment. The changing nature of PC entertainment software distribution, and the advent of console entertainment systems, has changed what software entertainment companies can do. You can't sell boxed entertainment anymore. And people who are playing games aren't always playing them on PCs anymore.

"Downloadable content and microtransactions for console based games are on the rise--look at Guitar Hero and Rock Band, where people anticipate downloadable Tuesdays, and you see huge numbers, half-a-million people downloading a song." Aerosmith's has outsold the band's albums on CDs over the years.