One of the big problems today with buying online, is people who list illegal copies of  DVD's and videos on Ebay and other sites. Unlike going to the store by you, you can't always be sure what your getting is authentic, in your region, and not a copy. Because of this problem people are even stating on their listings now that their DVD or video is not a bootleg or copy or import.
    When you go to a DVD or video listing, read the details. First make sure you see what region it is, and be on the lookout for ALL region, there are some legal ALL region but alot are copies. Foreign DVD's and videos can be legal but they are cheaply made. Then comes the hard part...
               
   DISTINGUISHING GENUINE DVD'S AND VIDEOS  FROM ILLEGAL COPIES:
First look at the picture and see if you see any chinese or foreign lettering, that is a sign that it is not an official US copy.  Another thing to look for  is  no picture.  With  DVD's and  videos, not having a picture is a really bad sign; having no picture probably  means  that the media has not been released officially and has been copied off television or from another DVD or Video. Unless in the case of someone who cannot upload a picture, but you should be able to find another listing that does have a picture. If you can't, then it probably is a copy. Be on the lookout for people who put a picture of a scene from their media from the TV; make sure you see a picture of the cover of the DVD or Video. An official DVD or video should have a UPC symbol and there should be small lettering around the little inner circle of the DVD. Also the name of the studio should be on the back cover. Even if you are not sure of the packaging, watching the media itself will help you determine if it is genuine by how the picture looks, if it is out of focus or hazy, it could be a copy.
    So, if you just be wise and check thoroughly when you go to buy DVD's and videos, it can be still well worth it to buy them on online, because you can save alot of money and get  your media mailed to your door.
     Like anything in life, the cons come with the pros. If people get informed and know what they are buying, the illegal media won't sell and they will diminish. So be wise and have fun buying!