Let's assume for a minute that this is not necessarily true and two blogs are pretty much the same. Fairly well written, good subject matter and relevant to many people.
Why is it that some have a readership in the 10's of thousands and other are in the tens.
Sure some are better than others. Some are more thought provoking. But if we line up two apples or two oranges, why is one fruit sweeter than the other.
I think marketing has a lot to do with it.
Marketing is usually a long road. Sure sometimes it just takes off. Sometimes it's viral. But in the majority of cases it takes repetitive and consistent effort over a fairly long period of time.
Some bloggers are quite active in the public speaking circuit and/or have written a number of books. They may network extensively in the real world and online. All of their activities feed each other. They increase the perception of value to the consumer (reader).
So if your product is as good as someone else's product and they are outselling you… perhaps you should focus on your marketing.
Yeah if you can make a better product you might gain market share that way. But your competitor might leapfrog you on the technology front.
Work on the perception of quality just as much as the quality itself.
(If a tree falls in the forest and no one is there to hear it, does it make a sound?)