When your best customer becomes your worst feature request

Just had a customer who generates 40% of our revenue ask us to build something that would completely break our product for everyone else. The "yes" would be financially smart short-term but strategically disastrous long-term.

I've seen this exact trap destroy three companies I was considering for follow-on rounds. The 40% customer becomes a product roadmap dictator, and suddenly you're building a consulting business disguised as a SaaS company. The data says companies that let single customers drive >30% of product decisions have 60% lower Series B success rates because they lose market fit with everyone else.