How often will google crawl my site?
What we all really care about is the Serps: how high our pages rank when people search for relevant key-phrases. For that relevant text in links, relevant pages from which to get links etc. are very important factors.
How fast pages are crawled is based on at least the following:
- how often your pages change and how often you add something new
- trust (does your site seem related to spammy sites or not, how new is the site, how new are the links to the site etc.).
How often your site changes
Google looks at the history of a site to determine how often pages, or sections of a website is crawled. If a website changes very infrequently, it will get crawled less. This means new pages will not get indexed automatically.
This can be a problem if a website does a major redesign after years of staying the same. This can be remedied by getting a link to new content on a website that is crawled often.
PR - google pagerank
Pagerank (or PR) is a measure google uses to determine the popularity of a website, and each page on that site. It was the basis of google's revolutionary growth as a search engine, but it has become less important to ranking since webmasters have tried to fool the system by 'artificially growing links'. These days PR is ONLY ONE of the factors in google's search algorithms.
Higher Pagerank means a higher statistical likelihood of more of your pages being crawled and more frequently. PR is only based on link-popularity. Links being related or not to your site has nothing to do with it. A link from a high PR site, will give your site a higher Pagerank.
Google trust is the newest factor determining where a page ends up on the SERPS (Search Engine Results PageS). New sites will not have trust. Older sites, with high PR (6 and up, probably) will have trust. Sites that get links from trusted websites, are going to get more trust themselves. Links that have been up a longer time, will be more trusted than links that have only just been put up.