Google is paid by the advertisers to show ads on their websites. Google pays commission to its publishers to show ads on their sites/blogs. It looks like simply, but it is not. Getting approval to your adsense application is a bit of difficult. A site with zero traffic is not useful for google or the publishers. You cannot earn a single penny if there is no traffic for your site/blog.
Before applying for adsense cross check whether your blog fulfills the standards set by google.
1. A blog must be at least 6 months old.
2. Minimum of 15 to 20 posts required (Own content preferred not copy-paste).
3. Do not add any third-party advertisement when applying for google.
4. Good traffic to a blog.
5. Don’t add unnecessary widgets in blog.