What does it mean that leading indicators for faster feedback?

Measure things that predict outcomes rather than waiting for outcomes themselves.

Example: A startup tracks monthly revenue to judge product-market fit — but revenue is a lagging indicator that arrives months after the decisions that shaped it. Sean Ellis's product-market fit survey asks one question ('How would you feel if you could no longer use this product?') and counts the percentage who say 'very disappointed.' That single leading indicator predicts sustainable growth 6 to 12 months before revenue metrics show it. The startup that measures only revenue is steering by the wake of the boat. The startup that measures the Ellis score is steering by what's ahead.

Try this: Pick one outcome you care about — a project deadline, a health goal, a learning objective. Write down the lagging indicator you currently use to judge progress. Now identify two leading indicators that would signal whether you are on track before the lagging indicator moves. Commit to measuring at least one of those leading indicators daily for one week. At the end of the week, evaluate: did the leading indicator give you earlier, more actionable information than the lagging one?