Over a one-month period, [data] shows that users Like content on their News Feed about 14 times, while their content is Liked about 20 times. Users send about nine personal messages and receive 12.
From a PEW study. Also interesting usage tidbit:
“Power users” — specializing in one of the activities describes above — make up between 20% to 30% of the Facebook population.
(Source: Mashable)
