Classify the failure
Use a short set of reasons: wrong service, wrong area, invalid details, no response, unsuitable timing or budget mismatch. Apply the categories consistently across sources.
Fix the earliest mismatch
If the wrong service attracts attention, change the ad. If coverage is unclear, show it before the form. If people are surprised by the call, improve the confirmation and contact expectations.
Review after the full sales cycle
Some homeowners need time to decide. Compare cohorts with similar maturity, and avoid treating every open enquiry as a loss or every form submission as a success.
Put it into practice
Review one recent group of enquiries with your sales team. Agree the quality criteria, identify the largest recurring mismatch and decide what to change before buying more traffic.