From my own experience these are the same people who will throw a "you know" in the same sentence as well for good measure :
"so she's like, you know, a total bitch you know, like I care you know and I'm like looking at her, you know, and she's like giving me a dirty look you know...
At the end of the sentence, if it ever comes, you have no idea of what they're talking about. Am I glad to be an introvert sometimes !
I think it's a trend, a fad, just like wearing your jeans under your buttocks so everyone can enjoy the sight of your designer underwear. Like you know, who cares ? In the end, quite annoying but a sure sign of the times. Very relevant question !