No matter how good your content is, how accurate your keywords are or how precise your microdata is, inefficient crawling reduces the number of pages Google will read and store from your site. Search engines need to look at and store as many pages that exist on the internet as possible. There are currently an estimated 4.5 billion web pages active today. That's a lot of work for Google. It cannot look and store every page, so it needs to decide what to keep and how long it will spend o