- Realize that the rest of the world does not, in fact, give a damn
It is easy to delude yourself that you are incredibly special. In fact, it is beneficial. But I hope that by working on an online presence you can show yourself that you really don't matter and won't be a superstar online. Delusions of grandeur, like that people care about what you did today, are damn common in the world of blogging. Understanding what one can and cannot do through online communication is worth exploring and busting those ego bubbles is a worthy task. Frankly, if you live and die by your online image, then something is really wrong with your self-esteem.
- To learn about marketing and publicity without having to face high stakes
Whatever bloggers would like to believe, an online "brand" is still highly marginal. Most people do not read blogs. Think about that. Online communities are deceptive in that they make it easy to imagine that one is reaching a wide audience. Think about TechCrunch for example. Well known and influential? I bet that most people you know have never heard of it - even those in the relevant industry. TC, a wildly successful blog is just the tip of the iceberg when it comes to people. It is easy to forget that online. (I think Eric Sink said it well: "Objects in browser are smaller than they appear")
Most employers won't bother finding out about your blog. Therefore I think this online thing should be about learning to market information - with little at stake. Failing doesn't really matter; you can experiment and not worry too much.
- To write about things you care about for yourself
I think the only reason to write is to preserve ideas you like, while perhaps helping some random people online. I think that is a good reason: I have been helped by random blog posts on many topics, and hopefully some of my posts will help someone.
"Monetizing" a blog is, I think, a rather bad reason to write. Not to discourage people (not that they would care), but putting up ads on a blog to me seems rather desperate unless you already have built up a huge audience. In terms of my quality of life, I don't see how making an extra 30 or 100 bucks a month are going to make any difference in my life. I have all the toys and ramen noodles I need and getting a few more does not matter. I like banner ads less than having to work an extra hour every now and then. (Obviously, if you are TC, this does not apply. But for $random_person like me, that is probably not going to be true.)