Though also viable, cute, and longing for a longterm relationship, there is often some unknown 'thing' in the placeholder's manner, ambition, world view, or timing that often prevents the placeholder from being "the one."
"I'm bored....Lets go find us some place holders" -- guys
Friend 1 - "God i fucking hate Michelle!"
Friend 2 - "Aren't u dating her?"
Friend 1 - "Yeah"
Friend 2 - "Well here she comes"
Friend 1 - "Hey baby!"
Often the user was just a place-holder for said ex and didn't know it/can't get over him/her.
guy:*awesome this is love ^.^*
The following Evening:
girl:Yeah...I'm back with <insert douchebag that just ruined your fucking life> and I wasn't really in love with you.
guy:*Holy fucking shit I'm going to kill myself as soon as I finish thinking this.*
Perfect example of a Place-Holder...often suicide IS the result of being a Place-holder.
Other results are binge-drinking and death threats.
"Theres this thing I have to do."
"Theres a lot of stuff in my head."
Those are placeholders..