9 Oct 25 
Slow websites don't feel broken, so nobody fixes them. Here's the business case for treating page speed as a revenue lever, with the numbers that make CFOs pay attention.
Here’s a conversation we’ve had more times than we can count. A marketing lead shows us their beautiful, expensive website and asks why conversions are soft. We run one test and point at one number. The site takes six seconds to become usable on a phone. The response, almost every time: “Oh, that’s a tech thing. I’ll mention it to IT.”
That sentence is where the revenue goes to die.
Speed Is a Sales Rep That Works Every Visit
Think about what a slow page actually does commercially. Your ads are paid for. The click happened. A real prospect, with real intent, is standing at your door. And the door takes six seconds to open. Some fraction of them, and it’s a bigger fraction than anyone likes to admit, simply leave. You paid full price for that visitor and lost them before your headline had a chance to work.
The research here is old, consistent, and still ignored. Google’s own data has long shown that as mobile load time goes from one to three seconds, bounce probability jumps by roughly a third; stretch to five seconds and it nearly doubles. Amazon famously calculated that every 100ms of latency cost them about 1 percent in sales. You are not Amazon, but your visitors carry the same phones and the same patience.
Why It Never Gets Fixed
Speed sits in an organisational blind spot. Marketing owns the traffic and the copy. IT owns the servers. Design owns the look. The load time is everyone’s problem, so it becomes no one’s problem. And unlike a broken form, a slow page never fails loudly. It just quietly taxes every single visit, every day, forever.
There’s also a vanity trap: the people who approve websites view them on fast office Wi-Fi with expensive laptops. The customer is on a mid-range Android on a train. The PageSpeed Insights mobile score exists precisely to simulate that second person, which is why we ignore desktop scores entirely in our audits.
The Reframe That Changes Budgets
Stop measuring speed in seconds. Measure it in money. The arithmetic is simple enough to do on a napkin: take your monthly ad spend, your click-through volume, and your current conversion rate. Now model a conservative 10 to 20 percent bounce reduction from getting your mobile load time under three seconds, which is the range performance work routinely delivers. For most businesses spending meaningfully on traffic, the recovered revenue pays for the performance work in the first month or two. After that it’s margin, compounding silently on every visit.
That’s why speed belongs in marketing’s budget conversation, not IT’s ticket queue. It’s not maintenance. It’s conversion optimisation with unusually predictable returns.
What To Actually Ask For
You don’t need to learn the engineering. You need to ask three questions of whoever builds your site. What is our mobile LCP in the field, not the lab? What are the three heaviest things on our most-visited page? And what would it take to get under 2.5 seconds? If the answers come back vague, that’s your real finding.
Fast sites aren’t a technical luxury. They’re the cheapest salesperson you’ll ever hire: no salary, no sick days, working every single visit. Treat the budget accordingly.
Want the napkin math done properly for your site and traffic? A speed-focused audit is a conversation away.