1. Positive ON-Page SEO Factors.
a. Keyword in URL.
b. Keyword in Domain name.
c. Keyword in Title Tag.
d. Keyword in H1, H2 and H3.
2. Negative ON-Page SEO Factors.
a. Text presented in graphics form only
No ACTUAL body text on the page
b. Affiliate site: The Florida update went after affiliates with a vengeance - flower and travel affiliates were hit hard - cookie-cutter sites with massive inter-linking, but little unique content. Subsequent updates have also targeted affiliates.
c. Over optimization penalty (OOP): Penalty for over-compliance with well-established, accepted web optimization practices. Too high keyword repetition (keyword stuffing) may get you the OOP. Overuse of H1 tags has been mentioned. Meta-tag stuffing.
d. Poison words: The word "Links" in a title tag has been suggested to be a bad idea. Here is my list of Poison Words for Adsense. This penalty has been loosened - many of these words now appear in normal context, with no problems. But watch your step.
e. Excessive cross-linking: within the same C block (IP=xxx.xxx.CCC.xxx)
If you have many sites (>10, author's guess) with the same web host, prolific cross-linking can indicate more of a single entity, and less of democratic web voting. Easy to spot, easy to penalize.
"This does not apply to a small number of sites" .. (this author guesses the number 10, JAWG) . . . "Hosted on a local server". . Matt Cutts July 2006.
f. Keyword stuffing threshold: In body, meta tags, alt text, etc. = demotion
3. Positive OFF-Page SEO Factors.
a. Page Rank: Based on the Number and Quality of links to you. Google link reporting continues to display just a SMALL fraction of your actual back links, and they are NOT just greater than PR4 - they are mixed.
b. Anchor text of inbound link to you.
c. Link from "Expert" site. Google patent - Big time boost (Hilltop Algorithm).Recently reported to give a big boost!
d. Site listed in Yahoo Directory: Big boost - You can get in by paying $299 each year. Many swear it is worth it - many swear it isn't.
e. Site Age - Old shows stability.
4. Negative OFF-Page SEO Factors.
a. Zero links to you: You MUST have at least 1 (one) incoming link (back link) from some website somewhere, that Google is aware of, to REMAIN in the index.
b. Link-buying. (Very good IF you don't get caught, but don't do it -when caught, the penalty isn't worth it.)
c. Cloaking: Google promises to Ban! (Presenting one webpage to the search engine spider, and another webpage to everybody else.)
d. Penalties - resulting from. Domain Hijacking(work with Google to fix).