If these books are postable.  I tried to use goo gone to clean off the price that was marked on the edge.

http://s1119.photobucket.com/albums/k634/bertie0228/

Why are the spines dark Bertie?  Goo-gone shouldn't have made discolorations to book covers.  Or is the adhesive so dense that the Goo-gone just smeared it around?

Will the black smudging come off?  With further wiping perhaps?  If the marks seem to be unremovable, then these books would be unpostable IMHO as the covers are "stained" and book posting guidelines for overall condition state "no staining".  But most likely, these would be acceptable to a member if offered in the Book Bazaar.

If, however, the smudging seems like it could be wiped off, even though the Goo Gone treatment caused the problem and does not eliminate it, then they aren't stains and IMHO these are postable.

Depends, I guess, on the nature of the black smudges...

Denise,

they marked the price with black grease pencils.  So when I used the goo gone it smeared .  I don't know why it was just those two books when I used it on over 40 books that I got today. 

I would consider them soiled and unpostable as long as that stuff is on there. Even if it isn't a "stain" it is "soiled" which isn't postable either.

I think your would have been better off to leave it alone if it started out as just a grease pen mark. Simple ink marks are usually ok - they are remainder marks. Now it looks more like damage than a remainder mark.

What if you tried to clean them with a regular cleaner, like Mr. Clean or something?  Spray on paper towel first and then wipe.  I've done that before and it's been fine.  As they are, I would be concerned of a RWAP even though they look to be in great condition otherwise.

Another cleaner option might be a cloth lightly damp with nail polish remover or alcohol.