If the anything they aren't making is money then it is a bubble and it will eventually burst. When growth in users is seen as orthogonal to growth in income th

If the anything they aren't making is money then it is a bubble and it will eventually burst. When growth in users is seen as orthogonal to growth in income then the whole thing will come crashing down. If growth in users can be consistently converted to growth in income then it's not a bubble. Many people are skeptical of whether user growth can be consistently converted. Very true observation on the effects of a burst bubble -- if it happens everyone will notice. No one is good at predicting the end of a bubble so it is generally better not to pay attention to the predictions until you start observing effects directly.