I don't use analytics on my personal sites for vanity metrics. I use it to see where people are coming to my site from and the stuff they seem to resonate with.
Upon a bit of introspection I found that for me, such things were just ways of stroking my ego. I just find it liberating to not really care or give much thought about what my audience cares about or who they are. I write first and foremost for myself, second to help others and third to have something to show to prospective employers.
What those metrics mean to oneself is different for everybody. Also, being a vanity metric and being useful are not mutually exclusive either.
What those metrics mean to oneself is different for everybody. Also, being a vanity metric and being useful are not mutually exclusive either.