Larry O'Brien posted an interesting piece as a response to Jackob Nielsen's post on Articles vs. Blog Postings. Jackob Nielsen's opinion was that experts should spend their time writing longer, complete articles instead of blogging. Larry shoots down Nielsen's theories based on his own experience, and I'll agree with Larry this time, if not for the same reasons.
I'd first like to point out that articles and blogs are not at odds with each other; you can do both and still get good results. I've written articles for magazines in the past and I'll say it is a lot of work and can usually take a lot of time. Personally, I admire those that have the drive, guts and patience to do that month after month. Blogging can certainly take a lot of time as well, particularly if you write the occasional long article, but not anywhere on the same scale. I favor blogging now not because it takes less work, but because I find it more useful for myself.
A lot of what I write about on my blog is about stuff I've learned (or am learning) during my own projects, and it's a great resource that I constantly search and refer back to when needed. So, while I try to write so that other people will find my blog useful, my primary drive has always been personal benefit: it provides not only the constant reference (so that I don't forget things), but it's also an excellent way to learn at the same time. When I force myself to write about a topic, I need to make things a lot clearer on my head and thus end up with a better understanding of what I'm writing about.
Monetary gain , or leads, while useful, have not been the main motivation for having this blog for me. To be honest, while I've gotten some work from my blog, it hasn't been all that much (I'd sure appreciate any leads :-)). Then again, that might be because I don't have all that many readers...
 Yes, I do have some ads on this blog through Google adsense, but if I told you what those ad clicks have amounted to, you'd be laughing ;-)