On the subject of quality, Google provides the following guidance:
• Make pages primarily for users, not for search engines. Don't deceive your users or present different content to search engines than you display to users, which is commonly referred to as "cloaking".
• Avoid tricks intended to improve search engine rankings. A good rule of thumb is whether you'd feel comfortable explaining what you've done to a website that competes with you. Another useful test is to ask, "Does this help my users? Would I do this if search engines didn't exist?"
Bing also emphasizes the importance of content and advises as follows:
• Ensure content is built based on keyword research to match content to what users are searching for
• Produce deep, content-rich pages; be an authority for users by producing excellent content
• Set a schedule and produce new content frequently
• Be sure content is unique—don't reuse content from other sources
