How fast should you follow up with a lead?
As close to immediately as you can manage, because somebody who contacted you has usually contacted two or three other businesses at the same time and the order of replies decides who they talk to first. A fast, plain reply beats a slow, polished one, and the difference is not close.
The reason speed wins
An enquiry is a moment of intent, and intent decays. The person who replies while the customer is still thinking about the problem gets to shape what a good solution looks like. Everyone who replies later is arguing against an impression already formed by somebody else, which is a much harder conversation to win.
Why good businesses are slow anyway
Almost never unwillingness. Enquiries arrive while you are with a customer, driving, or closed, and those are precisely the ones that get lost — not because anybody decided to ignore them but because the moment passed and the note was never written down. Resolving to be faster does not survive a busy Tuesday.
Make it structural
Decide what happens to an enquiry that arrives when nobody is free, and build that rather than intending it. An acknowledgement that sets a real expectation, a record so the enquiry cannot be forgotten, and a named next step. The goal is that no enquiry depends on somebody happening to see it.
What the first reply should contain
That you can help, or honestly that you cannot; what happens next; and when. Quotes, availability and detail can follow. The first reply is not a proposal, it is proof that a real business is at the other end and that the person is not going to have to chase.
Common questions
Is an automatic acknowledgement enough?
Only if it sets a specific expectation and that expectation is met. An acknowledgement promising a reply that never comes is worse than silence, because it spends trust as well as time.
What about enquiries that arrive overnight?
Answer them first thing, and say when you received them. Customers are reasonable about closing time and unreasonable about being ignored, which are different things.
Does this apply to quotes as well as enquiries?
The first response does. The quote itself can take the time it needs, as long as the person knows it is coming and roughly when.