How it works
Most stores number their orders sequentially, and every customer sees their own order number. So you place the cheapest order they have (shipping protection, a $2 add-on), note the number, wait, and order again. Subtract the two, extrapolate to 24 hours, and you have their real daily volume, for the price of a coffee.
The full method, including how to read it and when to trust it, is in the competitor order-volume playbook. Most "7-figure" stores you see flexing are doing a fraction of what they claim. This exposes the real number.
Two traps: some stores start order numbers at #1000 to look established (harmless, you measure the gap), and a few randomize order numbers to hide exactly this (numbers look inconsistent, abandon the read). Always take three readings and average them.