Woolly Shorts

Please could someone explain to me why I have received a plethora of unwanted emails from a hong-kong based manufacturer of knitted sportswear which, I understand, can be boldly emblazed with my personalised club emblem. Whilst furiously deleting this stuff I got to thinking (you can tell it's Sunday can't you) about what sports you would wear knitted stuff for (with the exception of golf where I understand that really tasteless pullovers are de rigeur). Obviously knitwear is not suitable for some activities - swimming for example, you don't really want a costume that's going to shrink when you hit the water now do you? And I don't really think that it's the ideal construction for rugby shirts, unless you are using steel wool...