I've been following this thread for a while, but really had nothing to contribute till now.
I went into my local bank the other day, and was talking to the two ladies who work there about the fact that now that I'm allergic to eggs, I'll be selling any excess eggs that my DH and kids don't eat. Well, they were both interested in buying eggs from me, and one of them said: "What kind are they?" So I said "We have large brown eggs, small cream eggs (bantams) and jumbo duck eggs." She said "Oh, I just want regular eggs." I just looked at her for a minute thinking "What, exactly, are regular eggs???" I knew she meant the large sized eggs, not the duck or bantam eggs, but the way she said it, like duck eggs or bantam eggs are gross, made me pause for a minute.
DH said I should just give them a few eggs for free (some bantam, large and duck) and let them decide after eating them which ones they want. Not sure how that might go over. Maybe if I gave them a dozen eggs, and threw in one or two duck and bantam eggs for them to try, that might work better.