There's also a huge opportunity in taking concepts that are working well elsewhere, and building them for the specifics of your market. For an early example, see Trademe in NZ (basically better rebay, and still completely dominant). If I recall, there's also a Berlin development house that basically does this at scale for the German market.

For a lot of people, winning in their country (rather than SF-bay-world-domination-hyperscale) is plenty.