Call it a fad. Call it immoral. If you have a hunch about it before the herd, and you can buy before they do, then you can make money.
Some people close to the proverbial situation appreciated that B2B was going to be hot before most of us had even heard of B2B e-commerce. They took advantage of that information inefficiency. And as an aside, it wasn't Wall Street analysts beating that drum. With most of these "new economy" trends, the push comes from the people.
As for the "wise" way to invest--it's not the adjective that matters most. Lucrative is. People who are value investors don't follow that path because it's wiser. They do it because they think they'll make more money. Momentum investors find that their way works for them. IMHO, whichever way makes you the most for the risk you can tolerate is the wise way.
Re Vanguard and costs: good point.