If, right at the start of something important, your partner (the other side) behaves even slightly unreasonably, you need to stop. Don’t hope the unreasonableness will go away later (or that you’ll simply have less contact).
Problems at the start = BIG problems later.
No excuses about how profitable the deal is or how promising the option looks. Unreliable partners will cancel all that out with what they do. And it’s hard to think up ways to protect yourself: you don’t know where the danger might come from until you get into it.
So when judging how promising any deal is, use this formula:
A deal’s prospects = all the deal’s pluses + the partner factor × 2
People really do matter more than all the material things. In business, at least.
This isn’t only about choosing the right business partner; that goes without saying. Half of your business will depend on your business partner.
But don’t underestimate the importance of the partners who take part in your business indirectly (your counterparties) either: customers, suppliers of goods or equipment, your landlords, internet and phone providers, website developers (especially the ones building an online store), couriers and transport companies.