You should write (essays, or tweets, or blog posts, but please, not "content") because you have something you'd like to say. Maybe it's a new idea, maybe it's a comment on someone elses idea, but it shouldn't be thought of as a product.

Think of the better writers on the internet (Maciej Cieglowski, Paul Graham, Glenn Greenwald maybe?) None of these dudes create "content"

37signals is a good example of this.