I think this problem is specific to today's web: I don't think slashdot and yahoo (or google) had a tribe.
That is, another approach to marketing is to build something that is just really good - much better than the alternatives. But this is extraordinarily hard to do, and it's much easier if you're in early, before it's mined out.
That said, whenever it seems that a market is stable and everything that can be invented has been invented, that's the very time that is ripe for something unexpected, perhaps coming out of left-of-field (eg. a disruptive tech).
It is true that a lot of startups underestimate the value of marketing ("creating a sale for tomorrow"). It seems that most people's idea of marketing is to contact bloggers back to back.
That is, another approach to marketing is to build something that is just really good - much better than the alternatives. But this is extraordinarily hard to do, and it's much easier if you're in early, before it's mined out.
That said, whenever it seems that a market is stable and everything that can be invented has been invented, that's the very time that is ripe for something unexpected, perhaps coming out of left-of-field (eg. a disruptive tech).