How odd, I was just going to post the same thing. I put mine in the middle of the mantle piece but it doesn't like the wood burning stove so I have moved it to the end of the mantle piece but now it looks wrong.
A lot can depend on where you bought it too. One year purchased a crass one from M & S - should have taken it back but the thought of the long queues there ..........
Poinsettas don't like draughts, over-watering or gas.
They do like a certain amount of time in the dark to prevent the bracts from turning pale. One way to prevent this is by putting a cardboard box over them. Not kidding you John.