As noted by expert internet analysts Heather Hopkins and Bill Tancer from Hitwise, last year's northern hemisphere Christmas period searches for 'ugg boots tall balck on sale boots' on the major search engines were up more than six-fold. So, as these analysts ask, what gives? As noted by Hitwise and others, sheepskin ugg boots have certainly become more popular in seasonal winter periods. Combine a particularly cold northern winter with a Christmas shopping frenzy and you have a sure-fire runaway ugg boots season. However, such a dramatic increase in ugg sale classic short boots chocolate popularity from one winter to the next must mean more than just an unusually cold winter. Commentators have noted the following factors that appear to be contributing to the massive increase in demand for sheepskin ugg boots: * The increased demand is not specific to only one country. The UK, US, Canada and Australia all experienced significantly increased demand over last year, so much so that many Australian suppliers actually ran out of stock and for a period were unable to meet the unprecedented local and export demand for sheepskin womens uggs clearance, sheepskin slippers, and other ugg variety items. * After the well-publicised 'Oprah's favourite things' show aired around the world in November 2005, that Christmas was a bumper sales year for ugg boots and sheepskin footwear items. No similar major media event triggered the winter run on sheepskin boots the following year, however. The only reasonable explanation for the continued ugg boots demand is that word of mouth and lifelong fans are driving the continued popularity of sheepskin sand ugg boot clearance. * Northern hemisphere ugg boots fans have also been quick to realise that ugg boots cost much less (a third of the price in some cases) than ugg boots and sheepskin slippers sold in local stores. For this reason, entrepreneurial-minded individuals have been buying Australian ugg boots in bulk for resale at a reasonable markup in the UK, Europe, US and Canada, but still much cheaper than local clearance woman's ugg boots stores.