Why the popular numbers are unreliable
There is a well known genre of statistic about response speed: contact within a certain number of minutes and your odds improve by some multiple. These figures circulate endlessly, usually without a source, frequently traced back to a single study conducted in one industry a long time ago, in a period when web forms were the dominant channel and messaging barely existed.
The underlying claim is almost certainly true in direction. Speed matters, and it matters most in competitive, high-intent situations where the buyer is contacting several providers in one session. What is not reliable is the specific multiplier, and building a target around a borrowed multiplier is how teams end up chasing a number that has no connection to their own business.