bc and wotlk keys, what to do?

[asdcxy]

i still have several boxes of bc and wotlk
but since every basic wow is a battlechest including bc and wotlk you don't need the keys anymore
i assumed that if i use a bc or wotlk alone i would also get the whole battle chest. but this is not working
so what to do with the old keys? are they just worthless?

[CimSlunt]

You could give me one so i can upgrade my vanilla

[asdcxy]

hm? my vanilla accounts also got upgraded to wotlk and i could even activate 10 free days cataclysm (accounts i used only for gold transfers)