I voluntarily subscribe to 1: "Concealed Carry", because concealment and self-defense are the main foci of my interest in firearms. Every issue has an article I find interesting.
I get the IDPA "Tactical Journal" because I like to shoot IDPA and joined. Love that large print!
To apply for membership in a local gun club (only a mile from my house!), I had to list my NRA membership number on the application, so I joined and will soon get whatever magazine comes with that---"American Rifleman" maybe. I had been contemplating joining for a while anyway, so the application merely changed "do it someday soon" to "do it now".
I occasionally buy single issues of "Combat Handguns" if I get wind of an article on a subject of particular interest to me.