eBay - how often do they run the £1 listings?

Hi folks, I'm sure many of you took advantage of the £1 selling fee offer from eBay, which is just about to expire.
I couldn't list all the items I wanted, so I'm pondering if I should wait for another similar promotion or just bite the bullet on full 10% fees... How often do you think eBay runs these promotions? Is there a chance to see another one before Christmas?
Thanks