Is facebook successful?

I had the great joy to listen in when John Ndege from Facebook stopped by Founders House the other day. Obviously he shared some good insights, but when he said the magic words: “Facebook is doing really well and is very successful” I couldn’t help myself. I had to ask him what that meant?

If you have 800 mil users what is successful exactly? What is the financial KPIs you are using? Like the average monetary value per user? What do you compare this to?

John Ndege did not give me a direct answer, so I share the question here. Which monitory or financial KPIs and at what level should they be for a company with a resource 800 mil users to be deemed successful?