Any ideas on what is wrong and how this can be fixed?
Aesthetics. The fastrunningblog is functional, but not beautiful. These days, people expect to see both. Your competitors all have beautiful web designs, plus lots and lots of features. Check out:
http://www.runstoppable.com/http://www.runningahead.com/http://www.coolrunning.com/log/index.shtmlhttp://athlinks.com/http://www.motionlingo.com/motiontrak/Most of these competitor sites offer oodles of database-driven stats, graphing engines, customizable templates, etc., plus the web design and graphic design are top-notch. I'm not saying that the Blog has to be this, but this is what you are up against when trying to recruit new members in the world of online running logs.
In my opinion, the Blog's greatest asset is the
people. There is a good amount of expertise here, but better yet, the people on the blog legitimately
care about each other. That is rare. The blog has heart. That is why the blog is as successful as it is, and if you can sell that, it will be more successful. Better graphic design and more tools will help too. And there is an amazing database being built that you can surely exploit.
But even if your site is never "beautiful" and flashy, just remember what the most successful running site is: LetsRun.com. The front page of this site is chaotic, ugly, and hard to navigate. The message board is utter chaos. But it is driven by the people, and elites regularly post there. As a result, it has an amazing amount of traffic.
Anyway, those are just some of my thoughts. Not sure if they are useful.