I'm probably one of the few, that purchase sight unseen and have been disappointed, and very pleasantly surprised. I'm an avid eBay buyer, and was quite happy with a 75 fat Quarter Box I got, with NO IDEA WHATSOEVER what the prints would be other than it would span the rainbow. The fabric quality was superb, the prints lovely and I was a happy camper.
Another instance, Quite mad when I bought low priced pre cut squares from one buyer, sadly everything was soaked with cigarette smell, badly cut and not all cotton, some pretty horrid hard crunchy stiff fabrics. Her feedback reflected my disappointment.
Yet another time I got a bunch of yard sale items that the seller had simply laid in a pile to show the prints, but I had no idea what the lengths would be, but knew they totaled about 16 yards. Being a scrapaholic quilter, I was still happy with the package, even though there were strips, squares and full yardages, some prewashed, other items in haphazard cuts.
My last eBay buy, I ordered 3 sets of 25 different Dragonfly prints totalling 75 squares, 3 of each print) and 1 of another color range precut 4" squares. The seller missed that I had two orders, and only sent 2 sets, the quality was awesome, though did not match the representative picture, when I emailed her saying they didn't match the photo, the seller told me to keep what she sent, and refunded my $.
My main point is, if you give an ACCURATE Description, such as UNCUT (meaning Selvage to Selvage) fabric, in varying widths of yardage, some under some over a yard, I think that you will still get buyers like me, if you give an idea of the prints, like all calicoes, plaids, childrens, etc.
That is generally what I look for when buying sight unseen, I don't want a bunch of Holiday themed prints, and would want to know that ahead of time, and general color groupings can be helpful, say a box of greens, or blues.
Hope this helps.