You need quality content on your blog to bring traffic and you can earn only when you have traffic. Just because you are running ads does not mean you are making money. You make money only when your visitors interact with the ads displayed on your blog. Having quality traffic ensures that you make money on the blog, and you can get quality traffic only when you have quality content.
You need to do SEO on your blog to bring quality traffic, and the first step of SEO is publishing quality content on your blog.
You need to do SEO on your blog to bring quality traffic, and the first step of SEO is publishing quality content on your blog.