Programs which send out
mass mailings can determine if an email address is
worth their resources to send unsolicited email to,
based on custom variables.
For the consumer, those that run spam filters,
frequently unsubscribe from emails and never go to the
sites promoted in the emails will be less likely to get
mailed, and those that are bad about getting rid of
spam, or frequently purchase from spam will get more
email. It allows for targeted mailings for the spammer,
and less email for those that are zealous in keeping
their inbox pure.
The benefit for the spammer is for the usage of fewer
resourced.
The benefit for the person hosting this site is that every
time someone verifies an address, it adds it to their
database. They can then sell lists of email addresses
without having to harvest them. Email addresses with
better statistics can be sold for more.
The benefit for the end user is that if they are
successful in avoiding spam, they won't get spam from
those spammers using this program to verify
addresses.
I will be posting the mySQL table format soon.