Imagine that your biggest client calls because they are having trouble retrieving their email. Or they want to know what their best-selling item is right now. Or their most popular blog post. Perhaps their website has suddenly gone down. You can hardly reply, “No problem, I’ll get back to you in 24 to 48 hours.”
And yet DNS gets away with it! If you need to move a website or change the way a domain’s email is handled, you’ll be faced with a vague 24 to 48-hour delay.