I'm on their mailing list. I'd say on average I get maybe 5 emails a week, and maybe a robocall every couple months (when they're running huge promotion discounts). Since I check my email several times a day anyway I never really notice it, and I figure, one of these times when I have extra cash I'll take them up on one of their offers.
The most recent one was something to the tune of for $100 they'd give you the basic pistol course, and $100 credit for their pro-shop. Sadly I didn't have the $100
I get a lot of emails every day so IMO one more isn't a big deal. If - like my dad - you only check email every week or so, it might seem like a lot.
Also, if you get sick of the emails, they do (as required by law) have an "unsubscribe" link on the bottom of each one.
si vis pacem para bellum