Ask HN: The most general, ideal strategy for SaaS success

Let's start by acknowledging that most SaaS products fail and there is no secret to success.

Irrespectively, if you were to start a new SaaS product in any industry, what's the most general advice you would give yourself in the past to succeed? Or if you think there is no general advice, pick a specific industry or niche you know really well, and explain how you would get started today.

I have a hypothesis that if you quickly gather analytics of the best performing SaaS products/services in your industry or niche and study them, you can learn how to either quickly catch up (i.e. a growing market that is not too crowded) or how to differentiate yourself.

Thoughts?