Is a list of people who like to pay less than face value for movie tickets valuable?
General rule of thumb for spam email is 0.1% conv rate, so if you blasted this leak list then you'd have 150K sign ups.
There is an entire data broker industry that relies on selling lead/contact information, so if anything there is a value savings on the hack. I've seen high quality contact (and assoc. company) data sell anywhere from $3 to $120.