From memory the Weakest Link was on for 45mins, I think this was forward planning for when it sold on the format, to fit in 15 mins of adverts, the typical 30min comedies are usually on UK Gold etc for 40 mins to include adverts. However I've definitely noticed more adverts of late, I accept adverts pay for the costs, but when there are 5 min ad breaks every 15mins and truncated programming people like me just won't bother watching them.