According to a study performed by DataPOWA, an AI-driven digital marketing agency specialising in sports and entertainment, Barcelona and Real Madrid are the clubs most valuable to brands in world football. The study - entitled the "POWA Index" - compares the sponsorship power of football clubs to their ranking on the Deloitte Football Money League - and the three highest-ranking clubs in terms of revenue, Barcelona, Real Madrid and Manchester United, also rank highest in terms of sponsorship impact. However, that's where the similarities between the two rankings end. While clubs like Bayern Munich, Manchester City and Tottenham all rank in the top eight on the Deloitte Football Money League, none of them feature higher than tenth on the POWA Index. Behind Barcelona and Real Madrid in first and second, respectively, are Manchester United in third, Arsenal in fourth, and Liverpool in fifth. Chelsea lie sixth, while Manchester City find themselves at tenth, despite havin...