Cost per mille, often abbreviated to CPM, means that advertisers pay for every thousand displays of their message to potential customers (mille is the Latin word for thousand). In the online context, ad displays are usually called "impressions." Definitions of an "impression" vary among publishers, and some impressions may not be charged because they don't represent a new exposure to an actual customer. Advertisers can use technologies such as web bugs to verify if an impression is actually delivered.:59
1. The big picture. Before you get started with individual tricks and tactics, take a step back and learn about the “big picture” of SEO. The goal of SEO is to optimize your site so that it ranks higher in searches relevant to your industry; there are many ways to do this, but almost everything boils down to improving your relevance and authority. Your relevance is a measure of how appropriate your content is for an incoming query (and can be tweaked with keyword selection and content creation), and your authority is a measure of how trustworthy Google views your site to be (which can be improved with inbound links, brand mentions, high-quality content, and solid UI metrics).
Keep your most important search pages (the pages you are using to target your most valuable keywords) “high up” in your information architecture: this means linking to them often in navigation elements and linking to them whenever possible from your most linked-to pages (e.g., make sure your home page and your site’s version of our hit snow study are linking to the most valuable pages on your site from a search perspective – your “money pages”). http://y2u.be/0Y6hluMPulU