When you are blogging for reviews, guest/paid posts, and other options available to earn money using your blog. You must have a good Domain Authority, Google Pagerank, Alexa Rank, Backlinks
Check your domain authority here.
Check Google Pagerank here.
Check your Alexa Rank here.
What are backlinks? Backlinks are links to your website on other websites. There are lots of ways to get backlinks. One way is leave relevant comments on other blogs that allow backlinks on comment submission. I have heard you can buy them, but I do not recommend that.