In my old days as an istock exclusive the christmas peak was around 20th November, then started to go down. By December 10th things became really quiet and by Dec 20th it was basically over.

On Adobe last year it was completely different. Very strong sales right up to New Year, then a little trickle until Jan 10th for orthodox christmas.

The christmas season also started earlier, many files being bought in July and August and even some already in March.