Your enquiries are fine. Your follow-up is losing them.
When enquiries stop converting, the first suspect is always lead quality. It is usually the second-most likely explanation.
The gap nobody owns
An enquiry arrives. Marketing counts it as delivered and moves on. Whoever answers the phone counts it as a job for later, because there is a customer in front of them right now. Somewhere between those two positions, a person who was ready to buy stops being ready.
This gap is structurally invisible. It does not appear in the ad account, because the conversion fired. It does not appear in the sales figures as a loss, because nobody logs an enquiry that simply went quiet. It only shows up as a vague, persistent sense that the leads are not very good.
An enquiry that waits four hours is a different enquiry. The person has already contacted someone else.
What to measure first
Median time to first human contact. Not average, median, because one enquiry answered three days later will distort a mean beyond usefulness. Measure it separately for in-hours and out-of-hours enquiries, and measure it from when the enquiry arrived rather than when someone noticed it.
Then measure what proportion of your enquiries arrive outside opening hours. For most appointment-based businesses it is far higher than expected, because people research services in the evening. If half your demand arrives when nobody is there and there is no automated response, half your marketing budget is funding a queue.
What to fix, in order
First, a same-session automated acknowledgement that sets an expectation: what happens next and when. This is not a nurture sequence. It is the difference between someone waiting and someone assuming you are closed or uninterested.
Second, a routing rule so every enquiry has one named owner rather than landing in a shared inbox that everyone can see and nobody is responsible for. Shared ownership reliably produces no ownership.
Third, a target for first contact, under five minutes during hours is achievable for most small teams and dramatically outperforms anything slower. Then a short sequence, two or three touches over seventy-two hours, that runs whether or not anyone is at a desk.
Why this is the cheapest fix available
Every other improvement in your funnel costs money to implement and then costs more money in media to exploit. Follow-up recovers demand you have already paid for. The enquiry exists, the intent existed, and the only thing missing was a timely reply.
It is also the fix that shows up fastest. Targeting and creative changes need a full buying cycle before the data means anything. A response-time fix changes your booking rate within weeks, because it is not creating demand, it is stopping the leak.
The honest caveat
Sometimes the leads genuinely are poor, and no amount of speed will help. The way to tell the difference is to fix response time first, since it is cheap and fast, and then look again. If booking rates move, it was follow-up. If they do not, the problem is upstream at targeting, and now you know that for certain rather than suspecting it.