I bought an ACEO last week from a fairly new seller and was thrilled to see that the artist had written a ton of information on the back. I emailed her and thanked her, because I was recently going through my collection, and realized that I have NO idea who most of my ACEOs came from (except for the ones I've bought from fellow artists on this board).
Anyway, this artist was blown away by my comment, and said that she thought most people just initialed or signed their cards, and that she was afraid she had written too much. I'm glad I emailed her, because more people should be doing that. Looking back, I now wish that I had saved the auction listings for some of these cards, because I'm now completely clueless as to who the artists are.
Anyway, I guess my long-winded point is that this re-seller probably doesn't know the artist names for that same reason. I have many ACEOs that have nothing but initials on them. If I wanted to resell them, I wouldn't be able to offer any information about the item at all.