Tools.
Two small calculators I built to think with. Move the sliders and see what changes.
You keep about £25 of profit for every £100 spent.
Sales313
Cost per sale£32.00
Return on spend1.25x
Break-even click cost£1.00
Profit per sale means margin after product costs, so the result is profit after ad spend. The chart assumes the same click to sale rate holds as costs change, which real campaigns rarely do.
Rate A0
Rate B0
Relative lift0
p-value0
Two-sided two-proportion z-test. A small p-value says the gap is unlikely to be chance. It does not say the gap is big enough to matter, so read the likely difference as well.