Writing can be a entertaining and profiable hobby but its good to have multiple sources of income when writing.  Several sites on the internet allow you to write and make decent income.  A popular writing site is E-How.com where you write articles and get paid based on the traffic to those sites.  They don't give a specific formula how earnings are equated but common sense would base the revenue on traffic and clicks on ads.  Your earnings get updated daily and are paid monthly from E-How not google itself.  The site is pretty professional and generating decent income is relatively easy.   Another writing site that allows you to earn money from your articles is Hubpages.com.  What I like about this site is that you write your article and can add amazon and e-bay links so that if your writing a review about a product you can actually provide a link to that product and get paid when someone orders it through your article page.  They also have google ads but all the earnings are paid directly through the affiliates not hubpages.  These two sites could earn you quite a bit of revenue why diversifying your writing income.