I've described why I blog several times previously, including within my very first blog-style entry back on September 4th (this blog just passed its 4 month birthday). The motivations are the same motivations that have pushed me to post online "papers" for about a decade now: Reputation, a bit of an outlet for thoughts (it is therapeutic), and of course to maintain or gain some namespace in the internet world (which really means PageRank these days), or at least to avoid namespace loss.
The namespace competition is much more competitive these days than it was a few short years ago, with the technical ease of blogging encouraging a lot of very capable entrants. If you're stand still, then you're falling behind quickly.
It really has been an uphill battle trying to get my thoughts noticed, but I'm finally at a remarkable point where I post something -- something written late at night in a brief interlude between ending "real work" for the night and hitting the hibernate button -- and discover that many thousands of visitors have passed through the next day. Often something makes its way onto the meme sites courtesy of one of the readers who thinks it's worth sharing (thank you kindly to those good folks). That's pretty neat, and is very rewarding.

It's especially satisfying given that I seldom spend more than 3 hours on an entry, even on the longer pieces, usually spreading it out over several days. On an average entry -- for instance the spelling entry (which also saw many thousands of visitors per day), or understanding daylight savings time -- I spend approximately 30 minutes, going back on re-reads to clean up the flow. There are also coffee-break length entries like this one.
I usually have the general concept fermenting in my mind for a while, and I type quite quickly so it's really just a process of transcribing it out and dealing with the technical errata (like Radio Userland's propensity for being overly helpful).
To make them a bit more visually appealing, I tend to take a few more oddball pictures during day to day activities than I normally would, but that's fun and is hardly a chore.
Entries are often much more readable after about a week, and if blogs had a wiki-style history you would see constant minor wording changes and paragraph reworks.
The few pieces that have earned considerable attention have been real eye-openers, and in some ways they encourage one to move to the dark side: It's very easy to see, for instance, exactly the type of content that earns a lot of attention, and it would be terribly easy to write pandering pieces, saying everything that the crowd wants to hear, and that which they want restated (which is what many use the popularity-measuring sites for -- to push their own agenda by promoting sites that state their opinion, and by silencing dissenting opinion by punishing those that don't. Look at Slashdot comment moderation as a great example of this).
It has been a great experience, and I greatly appreciate everyone who stops by. Thank you very much for a moment of your time.