I cancelled Sky on Tuesday or Wednesday last week. They left it 'till Saturday to call.
At the time of the cancellation I was offered 20% off TV and sports to stay (no minimum term) which I declined, having been on the 50% F&F discount for a year. Obviously they tried everything they could to alter my viewing options but realised when I said I only had Sky for sport they had few options!
The retentions guy offered me 30% with a 12 months minimum term, which I also declined. I mentioned the number of games appearing on BT Sport as well as the expense. He did the old 'I'll speak to my manager' thing (surely they all can't be speaking to managers when they say this?) and came back with the same discount but with no minimum term.
I again declined, another couple of minutes spent on hold, eventually 50% off TV and Sport was offered for 12 months, also no minimum term, which I accepted. It makes the base TV pack, plus sports, plus HD £31 p/m for me. Slightly more than the F&F deal, because the HD is no longer half price, but not enough for the 'bother' of finding someone to sign up as a new customer at my address.
It seemed very much like these were standard offer levels, certainly worth a try if you're out of contract. My initial 30 day cancellation period ran 'till 3rd Jan, so no danger of losing service!