1. Fake friends - act like they care, they don't.
You might have some stuff in common and talk them, but only because there is no one else to talk to. Once someone better comes along you'll leave your poster friends behind because after all, they weren't your friends to begin with.
2. Like a poster, you'll been seen with them in a picture but their not actually there for you when you need them.
3. Someone your seen with but they don't mean anything to you.
"I only eat lunch with my poster friends because I havn't found where I fit in yet."