Why does Harvard ask me why how I've learnt about them (i.e. by asking me to name specific alumni)?

On the transfer application, it asks me how I've learnt about Harvard and list them in order of influence. But if you've learnt about Harvard through an alumni or harvard student contact, it asks you to name the alumni if possible. Does anyone know why they ask me to name alumni? I'm assuming it's just to keep track of how people are hearing about Harvard. But I'm slightly confused why they want names. It shouldn't affect my application in anyway if I do name a Harvard Student Contact, right?