Metro POS, the POS standing for "piece of $hit" is basically a description of the outdated phones, service, and coverage areas that Metro PCS has to offer. A common nickname for the ghetto phone company in which you can have no credit, no job and no money to get crappy service with lots of dropped calls, double texts, and a very small service area for about $40 a month.
Often used by cheapskates, drug dealers, and those with bad credit who cannot attain a line with a reputable cell phone service provider.
Guy 1: "I called you like three times last night dude and your $hit went right to voicemail! $hit was CrAzY at the bar...you missed a good time!"
Guy 2: "Dammit! I was just at home sitting on the couch watching UFC, my phone didn't even ring!!! Damn Metro POS!"