Before spending anything on getting more enquiries, it is worth checking what happens to the ones you already get. In a lot of businesses the honest answer is: it depends who picks up the phone, and how busy they are that day.
That is an expensive gap, and it is cheaper to close than to generate more enquiries on top of it.
Speed decides more than quality of response
Someone who sends an enquiry is usually sending several. They are comparing, and the position you occupy in that comparison is heavily influenced by who replied first.
Replying within the hour puts you in a different category from replying tomorrow -- not because the answer is better, but because by tomorrow they have already spoken to somebody else and started forming a preference.
You do not need to have the full answer immediately. Acknowledging quickly, saying when you will come back with detail, and then doing that, beats a perfect quote two days later.
Write down what happens to an enquiry
Most businesses have never actually specified this. It lives in the heads of two or three people and varies with mood and workload.
Write it down. Who sees an enquiry first, what they do with it, how quickly, what information they collect, who prices it, who follows up, and how many times before it is closed.
The act of writing it down usually exposes the gap on its own. The most common one: nobody owns the second follow-up, so it does not happen.
Follow up more than once
Most sales that happen after a first conversation happen on a later contact, and most businesses stop after one. Not because following up does not work, but because it feels like pestering.
It is not pestering if it is useful and it stops when they say so. Three contacts spread over two weeks -- the quote, a check that they received it and have questions, and a final note that you are closing the file but they are welcome back -- is normal, professional, and more than most competitors manage.
That last message is worth more than it looks. It is polite, it creates a natural deadline, and it frequently gets a reply from someone who simply got busy.
Record why you lost
When an enquiry does not convert, note the reason in one word. Price. Timing. Went elsewhere. No response. Not a fit.
After thirty or forty, you have real information rather than an impression. If most say price, your pricing or your positioning needs work. If most say no response, the problem is inside your own process. Those are very different problems and businesses routinely guess wrong about which one they have.
You probably do not need software for this
A shared spreadsheet with the date, name, contact, what they wanted, what you sent, when you last followed up and the outcome will run a business a long way. What matters is that one exists and that one person owns it.
Software becomes worth it when several people handle enquiries and the spreadsheet starts disagreeing with itself, or when the volume is high enough that following up by memory fails. Not before.
Do this before spending on marketing
If enquiries currently go cold, more of them will also go cold. You will have paid to generate leads for a process that loses them.
Fix the follow-up first. It costs nothing, it works immediately on the enquiries you already have, and it makes every subsequent naira spent on marketing worth more. Any marketing supplier who does not raise this with you first is not looking closely enough at your business.