One reason why I started blogging (back in 2007) was to have an easy reference for myself about some specific syntax or config parameter name that regularly came up when working as a consultant at different customers. And access my scripts I used for troubleshooting things. While I couldn't connect my own laptop to their networks to copy anything over, my public blog web-pages were accessible at almost every site went to.

One exception was when I visited a customer in Shanghai, it turned out that my purely technical blog was blocked in China (at least back then) as it was hosted on a wordpress.com subdomain. I then migrated it my own domain and it was accessible in China too.

The other reason is definitely tech-marketing for my business, but hopefully with 99% quality and 1% noise :-)