Stop thinking that you are such an incredibly wide-ranging thinker with so many interests and insights that you cannot be pinned down to just one topic. The top bloggers are all wide-ranging thinkers. That's why they are interesting. The more information and angles you can draw from, the more interesting your insights are.
I challenge you to think of a popular blogger who lacks focus on their blog.
In the history of writing, everything has a focus. It’s a contract you have with the reader. You stay within the bounds of the reader’s expectations, and if you do that, you can write surprises that seem to stray from your topic, and the reader stays with you. Because surprises are fun. But if there’s no contract because there is no focus, then there are no surprises. Every great piece of writing works this way.
Think about it: Canterbury Tales. The topic is getting to the end of the trip. Or Moby Dick. Melville can write about everything—God, the American dream, fishing boats, marriage, mental illness—and he gets away with it because his topic is totally solid: Nailing the whale.
I challenge you to find a great piece of writing with no topic.
Even columnists stick to their focus. It's part of the fun. When you audition for a print-based column, you submit ten sample columns to show that you can be interesting in a variety of ways while still sticking to the main topic. Because it's hard to do.
You can write about any topic, but you have to link it to your focus. Look at my how–to posts. Most of them are only tangentially about how to do some career thing. Most of them are actually about something else. That's why they are interesting.
Look my blog: Do you need me to tell you to use bullets instead of paragraphs on your resume? No. Do you need me to tell you to stand up when you do a phone interview? No. Because there are 400 other writers who will tell you that. So I need to do something else.
But I can only get you to read me if you come knowing what you expect. So I always relate what I'm writing to careers. Sometimes, it's easy. I knew I wanted to write about my bed bug trauma. And I knew, quickly, that it was also about financial stress, which is, of course, a topic that's fair-game in the career world.
Sometimes you just need a little patience: I knew for years that I wanted to write about abortion. I listen to Brick, by Ben Folds 5 all the time, and I love his contribution to the discussion about abortion. I wanted to make a contribution like his, but I couldn't relate it to careers. Until I could. And then I wrote it.
Please do not tell me that you are just going to write whatever you want and you don't care who reads it, or if anyone reads it. You are lying to yourself. Of course you care. We each have a limited amount of time in our lives, and blogging takes some of that time. Your blog is not your journal. Believe me. I know. I”?ve been keeping a journal since I was five. I have seventy-five volumes of handwritten journals, and it is totally different than blogging because it's not public. The nature of a blog is that you are choosing to write publicly, so it is, by definition, for other people to read.
So, show some respect for people and pick a topic.
Also, show some respect for yourself. There are so many benefits you earn from blogging that do not require tons of pageviews. Here's a list of them. Mostly, the list is driven by being known for what you are good at. But for that to work you need to know what you're aiming for. What do you want people to know you for? Where do you want to go next? Answering those two questions is what will inform your blog topic and give you the focus for your blog.
Don't tell me you can't decide. Everyone knows where they want to go next. Even if it's probably wrong, you know, right now, where you're leaning. So write to that. Sure, it might change, but you need to commit to something, right now. Each day you have to wake up and do something. So you have to guess where to aim. We are all just guessing. Make your best guess and keep going in that direction until you find something else. And your blog is an expression of that commitment to yourself to have direction, even as you doubt it.