Slow pages don't announce themselves — visitors just leave. The cost shows up as lost enquiries and abandoned carts you can't trace back to a cause.
Speed is a conversion lever
Studies consistently show conversions drop as load time rises. Shaving a second off can lift sales more than a redesign.
Images are usually the problem
Oversized, unoptimised images are the most common cause of slow pages. Modern formats and proper sizing fix most of it.
Measure on a real phone
Test on a mid-range device and a normal connection, not your fast office laptop. That's what your customers actually experience.
The takeaway
Treat speed as a feature with revenue attached. Fast sites feel premium and sell more.