How often do you fail with online vintage?

I do approximately 85 percent of my shopping online, mostly with vintage stuff. This is not only because I'm amazingly lazy (editor-in-chief Kim France once referred to me as a slug and she was not wrong), but because there's a vast and interesting fashion inventory available on the Web that I can't always find on land. However, we all know this kind of shopping has its risks--items are one of a kind and usually not returnable, and if something doesn't work, you're basically stuck. For example, I would very very much like to own this awesome-looking jumpsuit (from my favorite online vintage shop,The Urban Collection), but it has the potential to be a colossal fail. Though knowing my measurements helps, there's a very real chance that it could make me look like a Goth, sausaged Barbara Eden in I Dream of Jeannie . How often do you take these gambles? And how often do you fail? (I'm about 5:1, successes vs. epic disasters, btw.)