Zen writes a little more on his metric of success that he enjoys:
it is very flattering that, over the course of a few years, close to a quarter-million times, other people felt it was a worthy expenditure of their time to stop by, read a little, or even comment. If Zenpundit was a book, I'd be a market success.
Zenpundit could not be a book in its current form; he is covering too much and hopscotching between his interests. However he is getting 500 to 1000 hits per day within a fairly narrow and precise field of interest --- non-traditional non-linear defense and security thinking that has an outsize impact on the real world. I have occassionally written within the same orbit as Zen, and I would like to believe that occassionally when I have written something insightful, it has more impact than a book in the remainder bin despite the fact that the audience may be smaller.
So how do you measure your blog's success metrics? Impact, audience, de-stressing mechanism or what?