Show The Work
We hate waiting without knowing why. This is the difference between a customer who tolerates friction and one who abandons the cart. Think about the last time you waited for something with a visible progress bar versus a frozen screen with no indication that anything was happening. The wait was probably similar in length, but your experience of it was not. That cue in the form of a progress bar, even when it's not perfectly accurate, gives you evidence of effort, which is something the blank screen doesn't.
This is a well-documented psychological pattern where people tolerate delay better when they can see work being done on their behalf, even if the work doesn't actually speed anything up. The visibility itself is the value, and it converts an unexplained gap into an understood process.
You might find this to be a useful composite example: imagine an onboarding tool that takes about a minute to configure a custom setup for a new customer. Instead of a spinner, it shows four labeled steps
• analyzing inputs
•building structure
•checking for errors
•finalizing output
With each one lighting up in sequence. While the actual time to complete doesn't change, the customers stop bouncing during that minute, because the system is visibly proving it's working, not stalling. So what?
You see, most companies optimize the variable of trying to make things faster. Sometimes that's right, but often the cheaper, faster win is to make the existing speed legible. Put this into practice by replacing silence with evidence. You can use status updates like, "Here's what we're doing with your request," or even a simple "We received this and are reviewing it". This buys you patience, which is precisely what you need from the customer at that moment.
Uncertainty is the enemy we too often choose not to confront.