The Three Types of Penalties: Algorithm, Manual and Filter Penalties
Preface: I've read this from several sources. Google themselves have said this much. I am not an authority though, so feel free to discuss/tell me I am wrong. When I learned about this, it made sense, and it helped me make changes to my SEO strategies. Worth a read.
Google has three major types of penalties. Ones due to their algorithm, ones given manually and ones that are periodic filters. I'll explain each for you all.
Algorithm Penalties
Google is making changes to their algorithm every day. This algorithm is running ALL THE TIME. The program correlates all of the data it has (indexed sites and information it stores about them) and it then uses this to calculate which websites are the "best". It then ranks websites in order of the best/most relevant. If your website drops in rankings due to the algorithm, it is usually not a big deal. It just means that your website isn't meeting the algorithm criteria anymore. The algorithm is always running so once you crack what the issue is, you can make the changes, then wait for your site to get re-indexed. It should then recover quickly, since Google will automatically recalculate your new ranking "score".
Manual Penalties
The most feared of them all. If your website gets the attention of actual HUMANS at Google, they will then look over it and if they see your website is violating your guidelines, they will slap it manually in the SERPs. The penalties are usually things like -30 and they last for a set period of time; e.g. 30-90 days. The most famous example of this is JC Penny when they were caught using very overt blackhat techniques. When receiving a manual penalty, you will be contacted by Google about your specific penalty. It is extremely unlikely you will be given a manual penalty because it is a lot of effort on Google's behalf to review sites. Note: UNNATURAL LINKS MESSAGE ISN'T A MANUAL PENALTY. It is a filter penalty. Read on!
Filter Penalties
This is the MOST IMPORTANT to understand of them all. Filter penalties include the following:
- Google Panda Penalty
- Google Penguin Penalty
- EMD Penalty (not sure if this is confirmed?)
- Unnatural Links Penalty
These are FILTER penalties, and they can be extremely devestating. They are algorithm's that are updated PERIODICALLY. So, the main Google Algorithm is running 24/7, right? Well, Google Panda isn't. Google will, time-to-time (about once a month on average) run the filter across all of their results. Websites/pages receive penalties accordingly. The reason they do this is because these are big, complex algorithm's. If they could run them 24/7 I'm sure they would, but it is a lot of processing power. If you get caught in a filter penalty, YOU NEED TO WAIT UNTIL THE NEW REFRESH. There will be mini refreshes directly afterwards but most people will need to wait until the main refresh.
What does this mean? It means you need to be patient. If you get slapped by Panda, it is because your content was not high enough quality. Lets say you fixed up the content within a week - you might expect to go back up, right? WRONG! You will have to wait until the new refresh. So don't get discouraged!
Less is known about the unnatural links penalty, I believe. If anyone wishes to expand on that in the replies, that would be great. It isn't a core aspect of the algorithm, and it isn't a manual penalty. It is more like a filter, which is why you get mass-amounts of letters sent out at once. However, I believe the recovery is a little more complex. If you get slapped by penguin, you need to fix your site and wait until the next refresh. If you get an unnatural link warning, that is just that - a WARNING. Google have said that if you fix the issues right away (1-2 weeks) then your website will NOT see a drop. So its probably two filters; one that runs across all of the websites, picks out the bad ones, and then a second filter that re-checks the warned sites. WATCH YOUR GOOGLE WEBMASTER MAIL ACCOUNT. It might save your site!
Also, fyi: this is how this guys site ranked #3 in 10 days. Yes his site is a piece of crap but its low competition. He will be slapped by penguin/panda/emd/all of them once their filters are refreshed. What does this mean for you? BLACK HAT TIME. You can still get QUICK RANKINGS! But, don't expect to keep them unless you're careful! The base algorithm isn't that powerful and can still be gamed - it is much harder to game the filters!
Anyway I hope this helps! Feel free to add your own comments in the replies section.