FB

On auction sites and online marketplaces, fb is often used to mean "feedback." After making a purchase, buyers can typically leave fb for sellers, including a quality score and comments. Sellers, for their part, usually like receiving fb from buyers, as good feedback makes a seller seem more reputable to other buyers.

Occasionally, you may see fb used to mean feedback in other, non-marketplace contexts. For example, a co-worker who is soliciting your opinion on an idea or project may ask you for your fb.

FB stands for "follow back" and is typically used on Instagram and Twitter. It is a polite way to ask a person to follow you after you follow him.

FB is similar to the LB acronym primarily used on Instagram and sometimes on Facebook. The acronym carries the same sentiment as the "I scratch your back, you scratch my back" saying. It is typically done to people with a lot of followers by people who want the popular person to follow him.