Building products is hard. Getting people to use your product is harder. Getting people to talk about your product is probably hardest. Thats the tipping point, thats when you go from a hypothesis to true value. You've made enough of a difference in someone's life for them to recommend you. Real people out there vouching for what you've built. There are no rules or books on how to get there. You learn by doing it and/or failing to do it several times.
The only pre-requisite I can think of is make something people want or can't be without once they use it. No, really. There is no product, engagement, growth hack, feature or UX trick that is going to help you get around this.
So you follow all the lean startup principles and have reached a point where you know what to build by speaking to customers, validating hypotheses as scrappily as you can and have to now convert them into a product.
This post is about thinking a bit deeper when you get to this point.
You're convinced your idea is worth investing in by validating it scrappily - no more hunches. You begin to employ causal reasoning - if A (surveys / interviews / research / tests) led to B (validation of opportunity), B should lead to C (successful product). You begin to gather resources to make C happen: You start investing in product development, fundraising, hiring and if you're technical - start thinking about frameworks, software architecture, infrastructure etc. You invest time, financial and social capital into gathering resources because you're now biased towards the opportunity succeeding. You gather these resources and then execute - build, launch, market, iterate.. and find out eventually if it actually succeeds or fails.
Here is my favorite theory against this: before you do any of this, try not to bias yourself towards success, consider that your product has already failed. Employ Null Hypothesis. Use the minimum viable resources that are already available to you (or gather minimally) to prove that your product can't fail.
There is a strong shift in thinking now, premature optimisation (design, branding, ux, hiring, funding, scaling...) that a lot of entrepreneurs and hackers exhibit due to confirmation bias are checked better than before. Causal reasoning turns into Effectuation. You're no longer hoping for something to be caused in the future, but you're actively trying to get to a result right now.