Since theater boxes were usually property of one or the other family, when nobody in that family was interested in attending a Play or some Opera, they would give to these people the opportunity of renting or selling the key for the play or the season.
There is a story about this crippled guy, Piero Balbi from S.Samuello, who, after a full day's work of breaking the broad bean, spent his nights selling box keys, helped by his sons.
And he was so good in doing it, achieving his own advantage along with his customers', that such a keen key seller never was again reported.
