Could it be that Kate Middleton is now the UK's - possibly the world's - most bankable fashion star? It emerged earlier this year that the Duchess of Cambridge's style choices has brought an astounding £1billion into the ailing British economy, eclipsing anything generated by supermodels, music stars and even Oscar winners (and that's no easy feat). What we do know is when Kate wears it, it sells. So Grazia Daily's done the Kateonomics and compiled a nifty summary of the effect she's had on sales and just how she did it...