Every new bloggers have been told they can earn money from blog ,some "expert" directly told you that "YOUR BLOG is MONEY".In many ways,it's true but that's just theory .In real life most blogger can't make a dime from their blog.From my experience,a blog will only earn you money only when you achieve certain level of achievement.E.G .certain level of popularity,SERP,SEO.etc.The level of earning