For a WSJ post.
Understanding what other startups are doing in your space is hugely valuable. It is information, not just competition.
The past efforts more than anything are experiments in user behavior and adoption. Use their lessons. Facebook was not at all the first social network, but it was deeply informed by the ideas and behaviors of the ones before. SixDegrees got too big too fast, as did Friendster. A nice problem to have! but for both of these it created huge cost and made thee adult users miserable. Facebook focused how they grew in the early days to targeted school-by-school launches.
Today’s players in your space tell you things about the market for money and adoption also. Big in Sweden like Spotify? Could work in the US. Geography is one way to transpose, and product market is another. Ordering cabs works great from mobile like Uber, maybe delivery or public transit are adjacent possibilities.
Of course direct competition tells you a lot too. If they are experienced and funded and ahead of you in time, it means you are probably too late. Look at the core facts, not the “oh they are doing it wrong” critiques. The key in this situation is pragmatism (don’t build a better search engine unless you are highly credible), and narrow the market definition till you have no direct giant competition. Mobile search, voice search, product search. Pick something where you can be the leader, and be great.
The best competition is no competition.