I was talking to my estate agent about this yesterday.
We are about to put our house up for sale and have selected the agent and so he came around to take photos yesterday.
I expected him to want to put it on immediately as he is fairly confident it will sell as there arent many houses like ours (standard 4 bed family home) for sale in our area.
He did state the rghtmove stat about highest number of browsers on boxing day but his feeling is that it reflects people being cooped up and bored over Christmas. He and most estate agents arent open until the first week of January so people might browse but wont be able to action it.
He advised that it would be best to wait to January - if it went on now we would have a week/10 days until everything shuts down for Christmas. He said we might be lucky to get one or two people who are already looking but the biggest problem is that it will then appear as an 'old' listing in January. Far better he said to go live in January and then far more people will be motivated to act, perhaps haviung thought about their housing situation over Christmas. So we will be going live on 6 January!