A product strategy is useful only if it constrains decisions, if everything is consistent with your strategy, you don't have a strategy. The test of a good product strategy: does it help you say no to reasonable requests? If not, it's a vision document, not a strategy.
"Strategy is not about what you'll do. It's about what you won't do. The hardest part of writing a product strategy is choosing who you're not building for, and that conversation is where most strategies collapse."
— Nora B., CPO at a Series C enterprise SaaS company
The five components of a useful product strategy
1. Target customer (specific, not generic): Not "product managers", "product managers at B2B SaaS companies with 5 to 50 engineers who write 3+ PRDs per month." The specificity defines what you build and what you ignore.