The full form of FPBP is first post, best post.
This acronym is used to represent the phrase “first post, best post.” It is used when the first response/answer is the best one for the original post.

Origin of FPBP
The exact origin of this acronym is uncertain. However, it is believed it was first used on the popular social media site 4chan and it has been used since at least 2016.

Other Meanings
The acronym is also used to represent some official businesses and project names. The other names that this acronym can represent are “Family Planning Benefit Program”, “Fudacja Porozumienie Bez Przemocy”, “Food for Progress for Bangladesh Project”, and “Framed Pseudo-Bayesian Priority”.

Conversation Examples
A text message conversation between two friends.

Friend 1: Did you see the thread on 4chan this morning regarding the new game?
Friend 2: No, was it helpful?
Friend 1: It was! The original post was one of the questions we had about gameplay and the fpbp applies so pay attention to that answer.
Friend 2: I will do that! Thanks!