the club's debts, paving the way for it to buy the world's most expensive players, such as Zinedine Zidane, Luís Figo, Ronaldo, and David Beckham. The city had previously rezoned the training grounds for development, a move which in turn increased their value, and then bought the site. The European Commission started an investigation into whether the city overpaid for the property, to be considered a form of state subsidy. The sale of the training ground for office buildings cleared Real Madrid's debts of €270 million and enabled the club to embark upon an unprecedented spending spree which brought big-name players to the club. In addition, profit from the sale was spent on a state-of-the-art training complex on the city's outskirts. Although Pérez's policy resulted in increased financial success from the exploitation of the club's high marketing potential around the world, especially in Asia, it came under increasing criticism for being too focused on marketing the Real Madrid brand and not enough on the performances of the team. By September 2007, Real Madrid was considered the most valuable football brand in Europe by BBDO. In 2008, it was ranked the second-most valuable club in world football, at €951 million (£640 million / $1.285 billion), only beaten by Manchester United, which was valued at €1.333 billion (£900 million). In 2010, Real Madrid had the highest turnover in football worldwide. In September 2009, Real Madrid's management announced plans to open the club's own dedicated theme park by 2013. A study at Harvard University concluded that Real Madrid "is one of the 20 most important brand names and the only one in which its executives, the players, are well-known. We have some spectacular figures in regard to worldwide support of the club. There are an estimated 287 million people worldwide who follow Real Madrid." In 2010, Forbes evaluated Real Madrid's worth to be around €992 million (US$1.323 billion), ranking them second only to Manchester United, based on figures from the 2008–09 season. According to Deloitte, Real Madrid had a recorded revenue of €401 million in the same period, ranking first. Along with Barcelona, Athletic Bilbao and Osasuna, Real Madrid is organised as a registered association. This means that the club is owned by its supporters who elect the president. The president cannot invest his own money, and the club can only spend what it earns, which is mainly derived through sponsorships, commercial partnerships,