Face

Scenario 1

Person 1 becomes a fan of something
Person 2 “likes” the fact that person 1 became a fan of that particular thing, so they like it.

Scenario 2

Person 1 becomes a fan of something
Person 2 doesnt care about person 1 but happens to like the same thing, so they “become a fan” also.

Facebook doesnt seem to understand the difference.

Notes