I heard a while back that the company who does the phone calls paid the NRA a fixed amount for the year and then keeps all or most of the money they collect. Could be wrong, but it was what I heard.
I don't know if this holds true for whatever company does the telephone fundraising for the NRA, but I do know that a number of years ago my state enacted a law requiring professional fundraisers to (a) submit their script to the state for approval beforehand, (b) stick to the script, and (c) tell people what percentage of their donations actually go to the organization they purport to be raining funds for. Unfortunately, our courts ruled that (c) is an unconstitutional infringement on something or other, so that part was tossed out. As for (a) and (b), I guess most of them do (a), but I don't think any of them do (b).
What came out of the discussions over our ill-fated law, though, was that most of these professional fundraisers work for police groups. And the fundraisers keep something like 80 to 90 percent of what they bring in. And the cops are happy with that, because 10 or 20 percent is better than nothing. I am of the opinion that the cops would do better just putting out a mass mailer, and asking people to donate directly to the department (or the police athletic fund, or policemen's benevolent association, or whatever). I won't talk to the professional fundraisers. If I happen to answer when they call (which only happens if I'm expecting a call from someone I want to talk to), I hang up. I've given up even trying to be polite.
I get a laugh out of the calls from the NRA. First, they always say "We," to make you believe that you're talking to an actual NRA employee. And they always refer to 'Wayne" by his first name, in words and tone designed to make you think that you're talking to one of Wayne's oldest and dearest friends.
As someone has already commented - they don't like it when you tell them that Wayne isn't the solution, Wayne is the problem, and that I won't contribute a nickel unless he's gone.