I disagree that the stats for Gadgets.se are close to GIS.se. Sure they have, at present, more users and more questions, however the ratios are quite dissimilar. For example they have almost a 2:1 ratio for answers to questions, whereas ours our nearly 3:1. So fewer questions, but more active participation on each. We also have more than 90% questions marked as answered. GIS.se is ranked 21 out of 28 at http://stackexchange.com/sites. Interestingly, it's only 2 ahead of gadgets but there are 5 below gadgets not getting the axe (right now).
The essence of the article is summarized in "So, essentially, a site needs either traffic or good answers, but if it has neither, we don’t think it will work.". Admittedly at this point we don't have so much traffic, but we do have good answers. Off course it's not my opinion that counts. :) The yellow flag you raise is well taken and we should heed it. More visitors, more eyeballs, more contributions well help. In my opinion more important though is great answers.
So what does that mean? Time. Don't worry about beating the "other guy" to answering the question. Spend the time to proof read your own contributions. Explicate, add examples, link to source material. A one or two sentence answer may be correct, but that doesn't mean it's good.
When you see a great answer, vote it up and add a comment about what in particular makes it good. This will encourage more of the same.
As for gathering traffic: when you discover a solution here to one of your problems, write about it somewhere else! Tell them how much of a time saver it was or how it expanded your understanding.
If there isn't anything to write about except "hey come help build this great thing" then the site really isn't working.