Momentum answers
Why do fast follow-ups win more clients?
Because at the moment a prospect is choosing who to hire, they usually have no other information about your business yet — response speed is often the only signal available, and it reads as a proxy for reliability. Jobs frequently go to whoever is easiest to reach and hire, not necessarily whoever would do the best work.
This is especially true for categories where the buyer can't easily evaluate quality in advance — most home services, for instance — so they lean on the signals they can observe, and responsiveness is the first one they get.