With around 300,000 to 500,000 monthly readers on my blog, I only earned about $1,500/mo from being a member of the Carbon Ads network. Plenty of other ad networks offer higher CPC (cost per click) and CPM (cost per 1,000 impressions) rates, but aren't as restrictive in the types of products that are allowed to advertise on your site. How much you can earn from ads also depends on the type of blog you choose to start, so be sure to do your homework and evaluate all of the top blog advertising networks in your niche.