Actually, NONE of the people in our dataset had zero friends. The x-axis starts at 1, not 0. The point is that resampling to remove the friendship paradox shows that there are many more people with single-digit friends than we expected.

Given mcintyre1994's comment, I think this still explains the same situation. People with single-digit friends are simply people who have friends blocked to apps but have multiple friends who've donated data.

No, we can tell when someone's privacy settings have given them a zero friend count, and they're not included in that aggregation.

All, since they're friends with the person who donated the data.

D'oh. Of course you're right, but simply substitute 1 for 0 and my base questions still stands.