It is particularly irritating in sportspeople, presenters and commentators as they are paid way in excess of the average salary of their audience precisley to tell them what it is they mean. The unspoken assumption is that the audience are already well aware of the 'gem of wisdom' or 'fact' (or see cliche) imparted by the 'expert' and that there really is no need to pay him or her £5000 an episode to provide such insightless insights.
Can be abbreviated to "you know" if she is in a hurry to get to a lot of important information.
further abbreviation while texting is commonly seen as "u no?" this version eliminates entirely the need or possibility for instant approval (real or imagined), requiring the textee to actually respond, or risk insulting her by not automatically taking her side.
Terry: She's my friend...
Lizzy: I don't have a problem with her, i just don't like the way she carrys herself. You know what i mean?