Here is a list of Google’s On-Site WebSpam Factors:
2. Links to Bad Neighborhoods: Linking out to “bad neighborhoods” — like pharmacy or payday loan sites — may hurt your search visibility.
3. Redirects: Sneaky redirects is a big no-no. If caught, it can get a site not just penalized, but de-indexed.
4. Popups or Distracting Ads: The official Google Rater Guidelines Document says that popups and distracting ads is a sign of a low-quality site.
5. Site Over-Optimization: Includes on-page factors like keyword stuffing, header tag stuffing, excessive keyword decoration.
6. Page Over-Optimization: Many people report that — unlike Panda — Penguin targets individual page (and even then just for certain keywords).
7. Ads Above the Fold: The “Page Layout Algorithm” penalizes sites with lots of ads (and not much content) above the fold.
8. Hiding Affiliate Links: Going too far when trying to hide affiliate links (especially with cloaking) can bring on a penalty.
9. Affiliate Sites: It’s no secret that Google isn’t the biggest fan of affiliates. And many think that sites that monetize with affiliate links are put under extra scrutiny.
10. Autogenerated Content: Google isn’t a big fan of autogenerated content. If they suspect that your site’s pumping out computer-generated content, it could result in a penalty or de-indexing.
13. Excess PageRank Sculpting: Going too far with PageRank sculpting — by no following all outbound links or most internal links — may be a sign of gaming the system.
14. IP Address Flagged as Spam: If your server’s IP address is flagged for spam, it may hurt all of the sites on that server.
15. Meta Tag Spamming: Keyword stuffing can also happen in meta tags. If Google thinks you’re adding keywords to your meta tags in an attempt to game the algorithm, they may hit your site with a penalty.
Here is an entire snapshot of the rest of Google’s Algorithm Factors.