Make money using mailing list

mailing list is an option supported by many web hosting companies, scripts and websites serving this service for free or for a little money as low as 1 $

by anyway make a mailing list

integrate it inside your website and ask your visitors to join you mailing list for recieving wahtever "newsletter-updates"
collect email addresses and you can use thim in one of the following two ways :

1- sell them to any advertising company .
2- use them for advertising for your own products or for your customers