...how many of these 30k customers that are waiting to be connected by the end of the year actually ordered in September/October?.

If you don't already have BT Broadband you can't even order Vision until that's all been connected and your line tested (presumably if it's not good enough you get told to fuck off and you have to go with Sky anyway!), which from my BT experience could be 2 weeks. Then you can order Vision, and god knows how long that takes. Virgin/Sky can have you completely connected in under a week.