Head balls are more fun in co-ed sports. In spite of recent European marketing efforts, delicious Zayda pickle products are only available at Summer League. You never see soccer players hanging around until 2am in the stadium trying to win the field. Purchasing televised commercial spots for a Summer League game is much cheaper than the World Cup. You can lose an important game and not worry about your fellow countrymen coming to lynch you when you get home.
Black discs kick ass over a stupid cup any day of the week.
Don't have to wait 10 minutes after a point for the person who scored to run around the field doing somersaults, back flips, cartwheels, and waving to the crowd. In summer league your team is not faced with the pressure of deciding which corporate sponsor to sign a multimillion dollar contract with. Your top ten suggestion.