When I started blogging, I looked through all the questions people had emailed me. It was a good way to start writing, but even though the answers were useful, the blog itself wasn't. Two years later, I had no subscribers.
Nobody knew why they should bother with my blog.
It all changed after I tried giving a few talks on different topics. With a talk, you're not just giving people useful information, you're making a bigger point. Inspiring change. You're claiming a topic, and synthesising a lot of different ideas into something coherent.
Most importantly, you're making a commitment to make it interesting to a larger, pre-existing audience, and getting in front of them.
Now people have a reason to read your blog.