A quote goes out. Nothing comes back. After a week or two it is mentally filed as lost, and attention moves to the next enquiry. This is the standard sequence in a great many small businesses, and it treats silence as an answer when silence is not an answer at all.
The customer's side usually looks nothing like refusal. They asked three businesses, received the quotes at different times, meant to compare them properly, and then a fortnight happened. Yours may have been the one they preferred. What decided it was not price or quality but which business was in front of them at the moment they had time to deal with it, and frequently that is whichever one got in touch again.
The reason nobody follows up is that it feels like pestering, and that feeling comes from imagining the wrong message. Asking whether someone has made a decision puts pressure on them and gives them nothing. A message that carries something useful does not read as chasing: confirming availability for the dates discussed, noting a detail worth knowing, checking whether anything in the quote needs explaining, or flagging that materials were priced at a figure that will not hold indefinitely. Each of these is a reason to make contact, and each leaves the customer better off for having received it.
Timing can be entirely mechanical. A short message a few days after sending, another a week or so later, and a final one closing the loop is enough, and the last is more effective than it sounds. Saying that you assume they have gone another way, that you will stop chasing, and that you would be glad to help another time, frequently produces a reply - because it is easy to answer, it removes any pressure, and it reminds them the matter was still open.
The reason this is worth systematising is arithmetic. These are people who already described their problem, already wanted it solved and already received a price. No advertising reaches anyone that far along. A business that follows up every quote twice converts a meaningful share of what it currently writes off, at the cost of a few minutes and a reminder in the calendar - which makes it the cheapest work available, and the most consistently neglected.