Depends on what I'm in the mood for-if it's WOF, I'll keep everything at least 3/4". If I have a lot of the same size scraps, I'll keep them all together if they are less then WOF. Then when I get a bunch I'll sew them all together as a crumb block or something similiar.
If I'm feeling completely overwelmed with scraps I'll only keep WOF strips ~1" or so.
I think if you let the person know what size scraps you have when you sale them it should be ok. If you say you have a box of crumbs, quilters will understand that you mean little tiny pieces. <hopefully>