[ano-ther]

Good observation that the noticing doesn’t get tested.

Would there be any benefit from knowing the notice rate though? After all, the intended outcome is increased sales by clicking.

[alsiola]

This is what I was driving at in my original comment - the intermediary steps are not of interest (from the POV of the hypothesis/overall experiment), so why mention them at all.

[ricardobeat]

Probably not, but then that hypothesis should not be part of the experiment.