Facebook Reciprocity
You like or comment on someone's post just so they'll stop liking or commenting on yours, like you're in some kind of Facebook back-and-forth that nobody asked for.
I liked your stupid post about your pet's hairball because you've been commenting on my boring memes.
I commented on your rant about your job just to get you to comment on mine.
I liked your post about your uncle's pizza because you kept liking my post about my cat's drama.