I have returned a greeting card, from another artist, because it was too dark. A few years ago cards were very nice, thicker card stock and glossy, but now they are thinner and duller. I have also had cards returned within 30 days, but I wasn't told the reason.
It's interesting/strange that when you remove prices from single cards they still show up with a price. In my case, with no price on single cards, it says 6.13 under the card, but when you open it, it shows only available in box sets. A customer would think they could get a card for 6.13. I tried both logged in and logged out and it's the same