Just use your blog as a means of expression. Does the artist worry about how to make a painting that will sell well and draw attention to themselves? No they don't. Instead they create a personal work of art, that is an expression of their internal selfs. If they make a small amount on the side then that's fine and dandy. If they don't get noticed they embrace the fact that they can express themselves freely and without constraint and chase another project.
You need to treat your blogging like this. Keep writing until you have your breakthrough. But never choose systematic manipulation of your expression (SEO) over the meaning of your writing. Just write and be happy and celebrate your small victories. Eventually the ball will start rolling. But if you've abandoned your true self just to make your blog profitable, you're not going to enjoy it as much if you intended from the beginning to pursue expression with integrity.