I like this site. My interests are very narrow - WW2 British sabotage and booby trap items as made by SOE and MD1, plus ordnance and equipment used by behind-the-lines forces and resistance units - but I occasionally see interesting posts and have gotten answers from knowledgeable members.
I don't know if anyone is trying to advertise the site on social media or anywhere else. I haven't tried looking. Sometimes it's as simple as putting a link to one of the threads on a Facebook Group or message board. That might be something the owner or moderators can suggest to all of us. For example there is a Weapons forum on the popular message board
www.G503.com, which is mostly about military vehicles but goes beyond that. And there are many FB Groups for all kinds of militaria collectors as well as military living historians and reenactor units.
I am in the historic military vehicle hobby and to a lesser extent, vintage motorcycles, and both have ageing demographics. Same goes for vintage cars and trucks. Advertising is important because there are many people who own or are fans of these things amongst us but they are not in the organized hobbies. Some don't know about our clubs or events. They don't always do internet searches where they will stumble on our websites. But even if there are shrinking numbers of people who like old stuff, we can try to grow the percentage who enter our world.