Isn't buying otc more expensive? Why would anyone do that just to keep the exchange rate low? What's the gain?
Correct, OTC is more expensive.
People usually buy from the exchanges to sell OTC.
Or, they find a OTC miner that can sell below bitstamp then they turn around and sell to retail buyers OTC (rather than making a tiny % selling on exchange).
Why would a miner sell below regular price? That doesn't make sense.
Bitcoin the "protocol/technology" in your analogy would be tcp/ip. To my knowledge, no one made a fortune buying "shares of internet."
I am sure many ISP provides made good money selling Internet to the people...