Counterexample: I was never interested in photo sharing before Instagram. I wasn't a good enough photographer. Now I can make my photos beautiful enough that I want to share them. Is this worth more than a few dollars to me personally? Yes. If I'm at all like a random person, then it's easy to see how Instagram is worth well over a few billion dollars.
Given the context of the article I think the argument can be made that: even _if_ people are willing to pay a couple dollars and in aggregate a billion dollars it doesn't mean that the money is being well spent or that the product actually provides value.
Thought at that point I think we're dipping into issues of free market and a consumer driven bubble.
