I’ve never really understood, what exactly is postybirb and its functionality in general? I’ve heard it mentioned several times, but not much really said about it.

It's a single program that makes it so you only need to upload a pic once to publish it on a variety of websites. I post on tumblr and twitter mostly since FA's uploading is a bit archaic, using this program makes it sooo easy there's no excuse not to post. So instead of navigating into each website seperately and uploading the same thing three times I can just do it once! =w= what a lifesaver.

Ahh, I see. That does make uploading much more convenient. :)