I started my Etsy shop a few years ago with just a handful of fabric postcards. There was a very popular blogger, at the time, who told me I would never succeed selling fabric postcards to quilters. Why not, I thought, but never did respond to her comment. There are many quilters I know who say they don't know how to make the postcards, and many others who just can't be bothered. Besides, my shop is geared to the whole world, not just quilters.
So just as a matter of information, to date I have sold over 130 fabric postcards in my shop and another 30 at a quilting bee.