That's a poor example, because "search engine" is the kind of business that is necessarily out on the far end of the scale. If we start travelling down the con

That's a poor example, because "search engine" is the kind of business that is necessarily out on the far end of the scale. If we start travelling down the continuum, next you'd hit something like "an app that makes lawyers more effective", then further than that "an app that makes patent lawyers more effective", etc. At each increment, you trade off market size and ultimate growth potential for less competition and lower marketing costs. Each of these niches can still be extremely lucrative (from the perspective of the entrepreneur, possibly less from the perspective of a VC who wants to make 100x). What's more, individual businesses leap up the continuum all the time. The first McDonalds was a barbershop-like business.