Can't remember the last time I looked forward to getting new promo material this way. I usually just unsubscribe to all of them.
I think they are just sent because they're usually automated, and the newbies may use them but simply saturate the content because they don't make many sales.
But if I get an email from a sponsor that rarely sends newsletters then I will at least take a look at it because it's probably something special and not just another "new FHGs" mailing.