We are seeing growth in online advertising which is driving the perception of a bubble regardless of whether one exists or not. The "We are in a bubble" argume

We are seeing growth in online advertising which is driving the perception of a bubble regardless of whether one exists or not. The "We are in a bubble" argument should be - Ad revenue is capped at a total # of dollars. We have seen various internet businesses take share from magazines, cable broadcasters, billboards which has led to unsustainable growth which will end soon. When it ends people will realize projecting 30%+ growth for website ad revenue is dumb and will lead to massive losses. The "we are not in a bubble" argument should be: Internet advertising is taking share from other sources and will continue to do so for a long time. Because online advertising allows you to buy products right away or customize ads to individuals, its more efficient. That efficiency makes advertising spending more likely to increase as a percentage of costs for businesses. A combination of those will help fuel continued growth in startups. Regardless of which you believe or a hybrid version, at some point internet advertising will reach its max and there will be a bubble followed by a crash. I have no idea whether that is happening now or will happen sometime soon or in 20 years. [edit] it is also possible that it will never happen