When I first discovered ebay, I was ecstatic.  I found all the clothing I was wearing regularly (namely, Ralph Lauren Polos) at such a deeply discounted price.  However, when my first polos showed up, it became clear that the majority of these that are sold on ebay are knock offs.  Here are the differences I’ve noticed having examined the real and the fake thoroughly:

   1. Just the general quality of the fabric is poorer, thin and flimsy and poorly made.  The stitching comes apart more easily, and each shirt is liable to fit differently, even from the same seller.  This isn’t incredibly helpful if you are not already familiar with the quality of genuine Ralph Lauren, but if you are, you can’t miss the difference.
   2. An easy one to notice is whether the “Ralph Lauren” tag in the back is thoroughly secured down.  Knock-offs have stitching along the top of the tag, genuines have the stitching on the sides.
   3. Most polos (all the ones I own) are made in Bolivia, and only have that in English on the tag.  There may be exceptions, genuine skinny polos made somewhere else, or with bilingual tags, but not that I’ve seen.
   4. The buttons on the fakes are not real mother-of-pearl.  They are more yellow and slightly transparent, and slightly larger than the real buttons.
   5. The fakes are usually too small, and shrink multiple sizes in the washer/dryer.
   6. The fakes come in plastic bags, and depending on the buyer, they all look different.  If these sellers were getting the polos from factory or outlet stores, they wouldn’t be bagged.  (There may be exceptions to this rule—I’m not positive on this one)

But these characteristics can not be easily noticed before buying.  So here are some more hints to avoid buying one to begin with.

   1. If there are many polos from the same seller, especially in the same colors, or large lots, they are unlikely to be genuine.  Some sellers do shop smart and get good deals, but no matter how smart they shop, they can’t get 50 polos in every size in the same colors.  It just doesn’t happen.
   2. Go to the Ralph Lauren website and look at the sale section.  Even those are still in the $50-60 range.  You can’t get that many polos and then afford to sell them “NWT” at $25 a pop.  I’m not saying you can’t get a genuine one for that price, or even lower, on ebay, but it takes searching.
   3. Finally, keep an eye out for pictures that are of professional models wearing the shirt (they’re from the RL website).  Most sellers (and I mean most, not all) will take a picture of the actual item (perhaps worn by someone, perhaps not) of their item.  Few just take the professional photos from the RL website.  

That is the best I can do for you for now.  But beware of thinking you can buy a knock-off and “get away with it”.  Perhaps you can, but don’t rely on that fact.  Anyone who has worn genuine Ralph Lauren can spot a fake a mile away.  And hey, preppiness is all about buying for quality and durability.  If you settle for a fake, why bother going for the look then?