WHAT MAKES "MUST HAVE" ?

It's interesting how certain pieces show up on almost every blogger: JC's Lita boot, Alexander Wang's Brenda Bag (among others), and the YSL Arty Oval Ring. . . What makes something a "must have" among style bloggers? Does seeing it on others affect your decision to buy it? . . . It seems almost every style blogger owns this YSL ring. If it were affordable I could see its appeal but it's easily $250. . . and many bloggers wear TWO! Did the YSL folks mail them out in multiples to bloggers? I can't imagine dropping that kind of money on this ring, especially because it's far from "unique" at this point.

What inspires your purchases? Does seeing it on your favorite blogger affect you? Celebrity? When does an item or trend get too tired to go on?

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