You're in the middle of a job. A call comes in. You think: I'll call back when I'm done — maybe 45 minutes. That seems reasonable. But here's what actually happens to conversion rates in that window.
Under 5 minutes: 80%+ conversion likelihood
A callback within 5 minutes reaches the caller while they're still in the decision moment. They haven't moved on. They haven't had time to get a competitor's quote. The job is almost certainly yours if your price is reasonable.
5–30 minutes: 40–60% conversion likelihood
Still good — but the caller has had time to call one or two other numbers. If someone answered while they were waiting for you, they may have already committed. You're now competing for a second choice.
30 minutes to 2 hours: 10–20% conversion likelihood
Most callers in this window have either booked elsewhere or cooled down. If the problem wasn't urgent, they've decided to research more options. You're now one of several callbacks they're fielding, and the advantage you had from being the one they originally called is gone.
Over 2 hours: under 5% conversion likelihood
At this point, a callback is mostly going through the motions. The lead has moved on in most cases.
The practical fix
You can't always call back in 5 minutes. But you can always auto-text in 60 seconds. That text buys back the conversion window — keeping the lead warm until you're actually free to call.