Funny how time flies. It seems that not very long ago (OK...10 years ago, which still isn't VERY long ago), we were deriding the concept of online advertising as naive. Who would advertise online, we wondered, other than those dubious shady people operating in the porn industry?

Pay-for-content was the way things were going to go. Well, here we are, just a few weeks after the New York Times, the last hold-out of pay-for-premium content, gave up that particular ghost, and we get the news that the online advertising market is being predicted to reach $50 billion by 2011.

There's a reason why people are queasy about predicting which technologies are going to fly and which ones are going to die. "People" are seldom right.

View the Yankee Group report summary here.