SE Site Evaluation

The search engines (SE) evaluate your site based on on-page criteria (content, alt tags, h tags, size of pages, how many pages, site/domain age, frequency of updates, internal linkage, outbound links), off-page criteria (inbound links) and a whole host of other criteria.

It looks that Google is starting to evaluate sites by how much time visitors spend on them (meaning, the faster your surfers hit the back button when they see your site - less score for you) and your site’s whois information.