One other thought to pass along . . .
I remember reading in Mindy's posts about this house cleaning that whether the card has sold or never sold is not part of the criteria here. A card that has never sold does not automatically make it suspect, there are thousands of cards on GCU that have never quite seen daylight so speak

A card that has sold before also does not automatically remove it from a card that may be returned to the artist as a decline or resubmission.
That's what I remember reading anyway as a response to someone's inquiry since this clean up began.
You'll find this list from Mindy on Page 3 of the forum thread at the bottom of my post:
Quote from Mindy on Jul 29th, 2011, 7:33pm:Thank you for your input and constructive discussion. Here are some answers to questions or issues brought up on one of the corrupted threads worth noting:
1. We'll define marketability as“suitable for sale”. A professional looking end product, with quality to compare in the greeting card market. Whether you like Hallmark or American Greetings cards is not the issue, it’s a level of quality to compete for the buying publics’ dollars. Good enough to sit on a rack in a store. Often purchasing online takes a leap of faith on quality so the pressure to not disappoint an online shopper and lose their trust is very important.
2. The bar has not been raised but merely established. It will not be hard to reach.
3. GCU is making these subjective judgements based on what we feel is truly marketable most of which are based on technical merits (or lack of), again "suitable for sale".
4. GCU is not choosing to limit nor differentiating among media/styles/forms of work that will or will not be accepted at this time. Photography is certainly under the most scrutiny.
5. Guidelines are on wiki with examples images and we will continue to update as a reference
6. Mainstream vs niche? – it is business as usual, as Doreen shares, with GCU embracing the uncommon, quirky, hard to find cards. So mainstream is certainly not a benchmark here. We are looking for quality in execution, a polished professional looking final product. Have quirky animal humor? Bring it on…when married with a quality image (in focus, good composition, etc) and related verse.
7. Lack of sales is not a factor nor is the level of professional training the artist has or lacks
8. NO cards are exempt – old, new, pending are subject to these guidelines effective immediately
http://www.greetingcarduniverse.com/forum/yabb2/YaBB.pl?num=1311637326/0 Just in case anyone wasn't online when this was announced or missed Mindy's responses. There are lots of answers in the 6 pages of this thread