$15/m with amazon affiliate links in a niche blog: http://www.archimodels.info (7.5k visits month). Unfortunately I didn't start the blog thinking about monetizing it. It's a very bad market (architectural students and teachers). Hopefully I can get $30 for 5h work every month (10min x 30days).
It's just a hobby that allowed me to learn about web development (that's not my work field).
