Testing a paid office hours slot for agency clients

I run 1:1 coaching for boutique agency owners and my problem is the same one everyone posts about: a big audience, a small number of buyers. So this quarter I stopped guessing and made the smallest change I could measure. I added one paid 45-minute office hours slot per week at €180, capped at four people, and told my list it existed. The interesting part was not the money. It was which people booked and which ones went quiet.