A good blog, like a good magazine, needs a reasonably narrow focus. Few people will continue following a blog that talks about cat care one week, Middle East politics the next, and computer software the week after that--unless the writer can tie all three to some common aspect (such as "the realities of the modern world from a radical conservative's perspective") and emphasize that aspect to make it obvious all posts come from the same basic point of view.
It is possible to write a blog that covers a large variety of subtopics. Look at major periodicals that have been around for decades: National Geographic; Good Housekeeping; Time Magazine. All cover a variety of topics that at first glance seem to have little in common, yet no one thinks it odd if National Geographic runs an article on caffeine next to one on the history of polar exploration. The secret is to have a clearly definable mission--whether that mission is to educate readers on people, their cultures, and their world; to show average Americans how to make personal and family life more fulfilling; to explore how a philosophy or religion relates to the real world; or simply to provide entertainment for lovers of literary fiction.
The most obvious advantage of the mission-oriented blog is that it's less likely to die for lack of new post ideas; how many things can the average blogger really say about "the view from my kitchen window"? (For a detailed discussion on how not to run out of ideas, check back to the March 23 post.) But unless the mission itself is obvious, readers may lose interest as quickly as with a "topics chosen at random" post. So "your mission, should you choose to accept it," is to write your mission-oriented blog according to the following hints:
Make your blog's mission match your business's mission--or some aspect of the latter. A veterinarian might write a pet-health blog; a community-development nonprofit could focus on positive aspects of architectural or educational trends. A relevant blog is good publicity for your business, helps establish your expertise in readers' minds, spreads passion for the cause, and also is the best bet for a topic you won't run out of ideas on.
Put a header on your blog that states its mission in one short paragraph. The "mission statement" for Good Writing is Good Business begins "Despite what many would-be novelists think, good writing is not easy. It is, however, vital . . ." (see above). When Web surfers discover an interesting post on driving for maximum fuel efficiency, and come back the next week to find a post on locating thrift stores, they won't be jarred by the apparent incongruity if the header has made clear that this is a blog on "everyday economical living."
Choose a blog title equally evocative of the mission. Even if you prefer a clever or intriguing title that doesn't make the mission obvious (in which case a descriptive header is doubly important), match it to the blog's overall tone. Beware of risque implications if your mission is conservative, and remember that "groaner" puns lead readers to expect plenty of humor.
Keep the tone consistent from post to post; it'll help maintain a cohesive feeling when topics vary. Define the typical response you want to evoke: belly laughs? Moral indignation? Sentimental musings? If you write your own posts, beware of trying to speak in a "voice" that isn't yours. Attempting humor without a gift for it is bad enough in a single article; in a series of posts, it'll drive both you and your readers crazy.
Every successful business has a mission. The wise business owner designs blogs--and all other PR and marketing materials--to provide maximum support for that mission.