Testers are products manufactured by the original designer of the fragrances
for promotional purposes only.  They are provided to retail stores to allow
their customers to sample the actual fragrance before buying it.  In some
cases, they are more concentrated and better for more people to attract.
The testers on this website are brand new, unused bottles with 100% off the
fragrance still in them without any damage or defect. Testers may come in a
variety of sizes and forms.  Some are offered in simply white or brown plain
boxes with or without a cap. Some might even have the word "tester" or
demonstration written on the bottle. Some Testers come without boxes, but are
packaged well to get to the destination safe, without a scratch.  Regardless of
the packaging, the quality of  the fragrance remains unaffected.  The contents of
the testers are exactly the same as in the standard full priced packaged items. 
The reason why they're so much cheaper is simply because the original boxes
manufactured by the company increase the price on the perfume.