To the Forum: Do you know how large of a staff is required to run a web forum like NamePros? I ask because I admire the user interface, the organization of topics, and the ease of use of the NamePros forum.
Relatively large. In addition to the staff you see (e.g., moderators), we also have a lot of staff you don't see. We have relatively complicated infrastructure as far as forums go. The forum software we use, XenForo, isn't designed for a forum of this size; we've had to rewrite large chunks of it. The most problematic portions have been rewritten using LuaJIT + Nginx--similar to what Cloudflare uses.
This sounds so cliche, but start small and scale. Forums typically begin with a single or a small number of staff and then grow as they go.
That's very true. Most of the successful forums I've encountered have started very small, typically with a single person.
You can start off with a free forum script like Simple Machines, phpBB or myBB. MyBB seems to have a large following of fans for various reason and many say it has surpassed the other 2 in many ways. Regardless, you can use one of those.
If you have the technical skills, I'd recommend starting with Discourse. Otherwise, phpBB tends to be a good choice. For whatever reason, MyBB are targeted a lot by high-profile attacks, so I wouldn't recommend that--although that doesn't say anything about the quality of the software itself; it just means you're more of a target.
You will have to pay people to post on it so that it looks active or else any traffic you drive to it will just leave. This sounds shady, but I see no way around it.
That's not true at all. The trick is finding a niche. For example, a lot of new forums devote themselves to small videogames. They'll pick a game, and as the game grows, so do the forums. If they're the first forum to target a particular videogame, there's no competition, and they become the authoritative community for that videogame. For example, minecraftforum.net started that way, and they were eventually bought out for what was certainly at least 7 figures. (The game itself was bought out by Microsoft for 10 figures.)
A hard lesson to learn when starting companies is that no matter how cool and innovative your product may be, it has to be something people actually want. If there are already a number of forums in your target industry, your chances of success are a lot lower. Instead, find a niche that's lacking a solid community.