MS Points are no longer used. Xbox has switched to a currency system. When you buy MS Points and add them to your account they are converted to your local currency which is used to purchase games and DLC from the Xbox Marketplace.
Seriously though MS Points haven't been around since July for almost all off us. MS thought they had ran their course and did away with them.
They were used to buy games and DLC and movies or what have you from the dashboard. They were like MS own currency. You had to buy MS points via cards or through your console through a credit card and the value you bought were changed into MS Points.
I didn't know people still had them
I am confused though. How can you have a score of 7550 and not know what MS points are?