How much does dick size matter?

Last night my friend showed me a picture of him fucking another chick. Pretty gay to do, he was pretty drunk and we both laughed. I noticed though (possibly even gayer) his dick was very large. Much larger than mine and i'm average. This guy also has 5 girls hes currently fucking.

I know girls are more likely to stay with you and come back to you if you have a big dick, just wondering if there are any other benefits the blue pill world keeps from us from learning.