Since this thread seems to have exploded in the past week, I'll try to briefly summarize my thoughts on this as a developer.
Namecoin's documentation is certainly somewhat lacking. This is because none of us specializes in documentation; we simply document things in our spare time when we're not coding. We'd love help on this; our website accepts pull requests (in fact, there's a link at the bottom of every page to submit a pull request). If improving documentation (and by "documentation" I mean all of the website) qualifies as "marketing", then by all means help us on this if you like. Probably best to talk to us on Matrix (or start a GitHub issue in the namecoin.org repo) before you expend too much time.
In the past, the few times that 3rd parties have done "marketing" on our behalf (or said that they're doing so on our behalf), the end result has been more harm than good. For this reason, I have learned to be extremely cautious when unknown people propose marketing operations for Namecoin.
In practice, the most effective public relations operations we've done have been speaking at conferences. (ICANN58 went really well, as did QCon London 2017 and DWS 2016. GETD#4 also went really well, although we didn't give an officially scheduled talk there.)
I think the primary barrier to wider adoption at the moment is simply that Namecoin is difficult to install and difficult to use securely. Hugo and I have been working on improving that situation. Once that situation is resolved, public awareness certainly becomes more relevant, as do various other issues that we face (privacy comes to mind here, and scalability will matter at some point too).
If anyone wants to help us with this but isn't a coder, taking some of the documentation work off of our hands would probably be a great way to help. Is there some information that should be clearly documented on the website but isn't? Create a GitHub issue for it or submit a pull request. Several of us are pretty easy to reach via Matrix (or IRC for those who prefer it -- our IRC is bridged to Matrix), and we're happy to facilitate stuff.
What I *don't* think we need is, say, a giant advertising campaign. I won't rule it out forever, but we're not at the point where that's going to be beneficial -- all it will accomplish is cause lots of technically unsophisticated people to try Namecoin, realize that it's too hard to use right now, and then not want to try it again in the future when the UX is more polished (and many of those people will sap our time on Matrix answering questions before they decide to call it quits).
Anyway, that's my take as a Namecoin developer. I look forward to hearing your ideas on Matrix.