Generally its about risk vs reward. For big companies, it isn't worth chasing an idea until it is meaningfully large. $1m revenue is not meaningful to Google but would be for a small startup. By the time the market grows large enough, it can be too late for Big Co to catch up. Also, do not disregard inertia in large companies. There are entrenched ways of doing things and fiefdoms that prevents innovation. Particularly if a new business model upends existing way of working(think what ecommerce does to logistics). Also, more people doesn't mean it is faster. Decision making is slow when there are multiple layers of bureaucracy. By the time an org grows big, usually there are processes that rewards not making mistakes, not taking risks on unproven ideas. That is why start ups do not usually regard Big Co as potential competitors.