I get offers like this all the time. It's free to the comedian, but once the comedian enters their fans' e-mail addresses into the system, the system owners get to use those e-mail addresses as they see fit, e.g., SPAM.
This website has a big directory of comics, all of whom unwittingly or not, sold out their fans' e-mail addresses for spam. Not me.
I keep my promises. Fans are precious, and I respect them.
I'll never make a dime.