40 Very Important Factors On SEO Here is the list of the most influential factors on SEO. I found this on another site. Sorted by Priority. 1 * HIGH * Title Tag - Description of Website 2 * HIGH * Domain Name 3 * HIGH * H1 tag or first headline of document content 4 * MID * Description Meta Tag 5 * MID * Keyword Meta Tag 6 * MID * Body of Text Italic 7 * MID * Body Of Text Bolded 8 * MID * Body of text generic 9 * LOW * Keyword Density 5-20% 10 * HIGH * Latent Symantec Indexing - Related words on topic 11 * MID * Sub headlines H2, H3 etc 12 * MID * Phrase order within the page 13 * MID * Keyword proximity of eachother 14 * MID * Font size +2 for sub-topics 15 * MID * Keywords within your alt text of image descriptions 16 * HIGH * Keyword early within the page 17 * HIGH * Keyword in links to other pages (on or off site) 18 * HIGH * Quality of other sites you link to 19 * HIGH * Topic of other sites you link to 20 * HIGH * Tree like structure of navigation 21 * MID * Internal links valid? 22 * HIGH * Number of links on the page itself (less is better) 23 * MID * Domain names you link to (Gov is best, then .edu, .org etc..) 24 * LOW * Web page size (IE: under 100k) 25 * HIGH * Hyphens in domain or file names more than 4 is bad 26 * MID * Page changing, more often updated pages prefered 27 * HIGH * Domain age 28 * MID * Page itself Age 29 * MID * Sites with more internal pages (IE: over 100 internal pages) 30 * MID * Page Theme 31 * MID * Frequency of updates themselves 32 * HIGH * Interesting title tag - Gets more SERP clicks than another 33 * MID * Appropriate links between itself and other pages 34 * LOW * Having a robots.txt 35 * LOW * Stating a physical address (Trust) 36 * LOW * Stating a support email address 37 * LOW * Describing every image 38 * LOW * Naming the images themselves thematically 39 * MID * Keyword in name of page itself 40 * MID * Document within a related folder or subdomain Credits to original author.