Gawker has a great story that defeats the recent "bloggers die of heart attacks" story. Those heart attacks happened because the people were not healthy, not because of blogging.
Here's a listicle from my favoritest of favs:
1. Bitching and moaning alleviates stress! "As social creatures, humans have a range of pain-related behaviors, such as complaining, which acts as a 'placebo for getting satisfied.'"
2. It gets you high. "Blogging might trigger dopamine release, similar to stimulants like music, running and looking at art." (Meta-blogger Emily Gould said as much in the NYT Magazine.)
3. If nothing else, there's the placebo effect: "Cancer patients who engaged in expressive writing just before treatment felt markedly better, mentally and physically, as compared with patients who did not."
4. Instant feedback, unlike your diary: "Unlike a bedside journal, blogging offers the added benefit of receptive readers in similar situations." Sharing is caring!