Do you like raindeer sweater?

What would Bridget Jones think if she saw Mark Darcy in his silly reindeer sweater this year? I think she would have thought, ok, he knows reindeers are SO IN this year, he just chose the wrong brand of the right garment!



...Because reindeer sweaters this year are everywhere and we all love them. Snowflakes, reindeers, everyone searches for those sweaters on sales now.
And I was wondering today: how do we know that the reindeer sweaters are in? How come we all (or, at least the majority) like them all of a sudden? Of course, one can say, is all about fashion with capital F, big designers, look at D&G F2010, it all started there. The problem is, I dont think the million of girls who search for that sweater in Berschka's and Zara's, I don't think those girls have actually SEEN that D&G collection. And yet, they like the sweaters.
I think it is much more trivial. I think we see same types of clothes in several shops and we subconsciously start to like it. The more we see it, the more we like it. And I swear, if only I own one day few different clothes brands, I will surely make an experiment on this topic! I just need to think of a symbol hidious enough to make it easy to verify. Any ideas?

PS: and the above does not mean I think that reindeers are hidious. I think they are cute!