F1. Who wrote your letters of recommendation and why?
Most MBAs chose their current direct manager. Often the school will ask for it, and often this person knows the MBA's work best. Sometimes, circumstances prevent an MBA from choosing their current direct manager, so they will chose a former direct manager.
There is significant debate about whether non-professional references are a good idea. That said, a number of people used mentors, professors, friends, or community service managers/peers.
There is a vocal minority that chose recommenders based on title. They had problems getting this senior person's attention, but felt it was worth it.
There's a fairly wide diversity of types of recommenders. Many MBAs mentioned that they tried to bring in differing and diverse perspectives of themselves through their choice of recommenders.
Chose people who knew me well rather than people who had impressive titles
Chose people who had impressive titles
Chose my direct manager and a high-level executive; used them to show a portfolio of who you are
Peer; Friend; Direct Report
Choose one professional recommender and one other; direct supervisor + business partner/friend
Recommenders who will put in the time
Spread the pain among many people
Tried to not burden any one person; also give a diverse perspective from multiple people