Do you mean I should have specified more clearly that I was asking for statistical data on the adverts which had already been posted and taken down, rather than probabilistic data on all adverts which might be posted in the future?

I wonder if there is a market for a pedant's Questions Answered service, where SWITCH NOBOYDIE is never assumed, and a carelessly phrased question can result in entirely the wrong answer. It would be a lot of fun to work for, if nothing else.