I don't know about you all, but I'm quite grateful to have this site as a resource. I feel like it is starting to enter a decline, which has me worried. I see fewer good questions being asked, and less activity. We are even down to only 2 moderators! What can we do to help this site to grow?
Let me give a few interesting tidbits. It turns out that site views are up, but questions are down. Thus, I think we are attracting people to the site, but no one seems to want to stick around for more than just getting the answer to their question.
I think we need to see if we can do something to increase the number of good questions on this site. Perhaps we could go with a theme, as we have tried to do in the past?
The original question was from 2015, but since there is recent interest:
My evaluation of the current state of things (mid-2017) is that everything is fine and we don't need to do anything. I look at the history of activity on the site and I see seasonal cycles and an overall consistent upward trend.
I recommend against specific promotional activities. (The cost is that we annoy people the way all advertising annoys people sometimes, and look like we have some incentive to "drive eyeballs to the site" or such.) It's not broken; don't fix it.
This isn't much of an answer, but I think that the low participation rate is a natural consequence of the design of all the Stack Exchange sites. Since most questions that might occur to people have been answered already, the rate of questions being asked has declined, and a lot of the questions that do get asked are of lower quality. This tends to turn off people who might otherwise be attracted to the site. It doesn't help that amateur radio is a mature field, and so new topics evolve slowly.
That's how I see it anyway; my opinion plus $2 will buy you a cup of coffee...
Area 51 lists hundreds of formerly very active folks that are no longer active for some reason. Someone wanting to increase the activity might consider encouraging some to come back. Possibly, find out if there was a reason for leaving that no longer exists. (I asked PearsonArtPhoto (a former moderator) some time ago (in another meta post), and I doubt whether he is interested.)
eHam.net has a Links page for listing ham-radio related websites there. You just pick the correct category, add the URL, and write a brief and appropriate description about it. If someone wants to do that, I suggest you include a question-and-answer site in the description. Perhaps some text from the main tour page would be appropriate.