I would like to do, when A2 changes to "Yes" everytime, B2 increases by 1. But the hassle for me here is, If A2 changes back to "No", B2 should remain 1, and when A2 again changes back to "Yes" the second time, B2 becomes 2 (increment by 1). so on and on..
Context: Why I want this?
A customer email@example.com subscribed to newsletter, hence firstname.lastname@example.org is subscribed ("Yes") and the subscribed time is 1.
The same customer now unsubscribes from newsletter, hence email@example.com is unsubscribed ("No") but since he had previously subscribed once, the subscribed time is 1.
The same customer now again subscribes to newsletter for the second time, hence firstname.lastname@example.org is subscribed ("Yes") and the subscribed time is 2.
And so on .. if unsubscribe again, times remain same 2, if subscribed again for third time, times changes to 3