Google更新了PageRank，终于换域名后一度为0的E-space恢复成了4。
Skype讨论组里有人问PR有什么用，且听枫吟说主要能决定相同关键词下的网页在Google搜索中的排名次序。为此我搜索了一下，找到了SEOmoz上关于Google Search Engine Ranking FactorsV2版本（发布于2007年4月2日），也就是决定Google搜索排名的关键因素说明，同时对每个关键因素做了相应解释和权值统计，并且还有众多专业人士做了评论和建议等等，如果你关注SEO，那么这篇文章绝对值得你细读。
同时还找到了一个按关键因素顺序排名的列表：Ranking Factors Simplified Quick Reference，更加直观，方便，特此摘抄（由于里面英文很简单，就不做翻译了），其中第一行的分类解释如下：
类型：Keyword = 关键字，Page = 网页，Site = 网站（域名），In-Link = 友情链接，Negative = 负面因素
重要程度：High = 3-4+，Medium = 2-3，Low = 1-2
认同度：Yes = 高认同度，Somewhat = 平均认同，No = 高争议
| # | 类型 | 关键因素 | 重要程度 | 认同度 |
| 1 | Keyword | Keyword Use in Title Tag | High | Yes |
| 2 | Site | Global Link Popularity of Site | High | Yes |
| 3 | In-Link | Anchor Text of Inbound Link | High | Yes |
| 4 | Page | Link Popularity within the Site’s Internal Link Structure | High | Yes |
| 5 | Site | Age of Site | High | Somewhat |
| 6 | Site | Topical Relevance of Inbound Links to Site | High | Somewhat |
| 7 | Site | Link Popularity of Site in Topical Community | High | Somewhat |
| 8 | Negative | Server is Often Inaccessible to Bots | High | No |
| 9 | Keyword | Keyword Use in Body Text | High | Somewhat |
| 10 | In-Link | Global Link Popularity of Linking Site | High | No |
| 11 | Negative | Content Very Similar or Duplicate of Existing Content in the Index | High | Somewhat |
| 12 | Page | Quality/Relevance of Links to External Sites/Pages | High | Somewhat |
| 13 | Site | Rate of New Inbound Links to Site | High | Somewhat |
| 14 | In-Link | Topical Relationship of Linking Page | High | Somewhat |
| 15 | In-Link | Link Popularity of Site in Topical Community | High | Somewhat |
| 16 | Negative | External Links to Low Quality/Spam Sites | High | Somewhat |
| 17 | Keyword | Relationship of Body Text Content to Keywords (Topic Analysis) | High | Somewhat |
| 18 | Keyword | Keyword Use in H1 Tag | High | Somewhat |
| 19 | Page | Age of Document | High | Somewhat |
| 20 | Negative | Duplicate Title/Meta Tags on Many Pages | High | No |
| 21 | Negative | Participation in Link Schemes or Actively Selling Links | High | No |
| 22 | Negative | Overuse of Targeted Keywords (Stuffing/Spamming) | High | Somewhat |
| 23 | Page | Amount of Indexable Text Content | High | Somewhat |
| 24 | Site | Relevance of Site’s Primary Subject Matter to Query | High | No |
| 25 | In-Link | Topical Relationship of Linking Site | High | Somewhat |
| 26 | In-Link | Age of Link | High | Somewhat |
| 27 | In-Link | Text Surrounding the Link | High | Yes |
| 28 | Keyword | Keyword Use in Domain Name | Medium | Somewhat |
| 29 | Page | Quality of the Document Content (as measured algorithmically) | Medium | No |
| 30 | In-Link | Internal Link Popularity of Linking Page within Host Site/Domain | Medium | Somewhat |
| 31 | Keyword | Keyword Use in Page URL | Medium | Somewhat |
| 32 | Keyword | Keyword Use in H2, H3, H(x) Tags | Medium | Somewhat |
| 33 | Page | Organization/Hierarchy of Document Flow (i.e. broad > narrow) | Medium | Somewhat |
| 34 | Negative | Very Slow Server Response Times | Medium | Somewhat |
| 35 | Site | Historical Performance of Site as Measured by Time Spent on Page, Clickthroughs from SERPs, Direct Visits, Bookmarks, etc. | Medium | Somewhat |
| 36 | Site | Manual Authority/Weight Given to Site by Google | Medium | No |
| 37 | Keyword | Keyword Use in Alt Tags and Image Titles | Medium | Yes |
| 38 | Site | TLD Extension of Site (edu, gov, us, ca, com, etc) | Medium | Somewhat |
| 39 | Site | Rate of New Pages Added to Site | Medium | Somewhat |
| 40 | In-Link | Domain Extension of Linking Site (edu, gov, com, ca, co.uk, etc) | Medium | Somewhat |
| 41 | In-Link | PageRank (as measured by the GG Toolbar) of Linking Page | Medium | Somewhat |
| 42 | In-Link | Temporal Link Attributes (when in time the link was created/updated) | Medium | Somewhat |
| 43 | Keyword | Keyword Use in Bold/Strong Tags | Medium | Somewhat |
| 44 | Page | Frequency of Updates to Page | Medium | Somewhat |
| 45 | Negative | Inbound Links from Spam Sites | Medium | Somewhat |
| 46 | Keyword | Keyword Use in Meta Description Tag | Medium | Somewhat |
| 47 | Negative | Low Levels of Visitors to the Site (Measured via Toolbar, Clicks in SERPs, etc.) | Medium | Somewhat |
| 48 | Site | Number of Queries for Site/Domain over Time | Low | Somewhat |
| 49 | Page | Number of Trailing Slashes (/) in URL | Low | Somewhat |
| 50 | Page | Accuracy of Spelling & Grammar | Low | Somewhat |
| 51 | Page | HTML Validation of Document (to W3C Standards) | Low | Yes |
| 52 | Site | Verification of Site with Google Webmaster Central | Low | Yes |
| 53 | Keyword | Keyword Use in Meta Keywords Tag | Low | Yes |
不过国内眼看着是不能用Google.com了，不知道蹂躏之下的.cn是否会采用另一种算法。
