It might happen your website or blog suddenly started drastically losing traffic and within few weeks it came down to nearly zero. It also might happen that you intentionally has not done any thing that is known to you as bad. So, to avoid getting penalized by Google or those webmasters with excellent websites or blog suspecting Google might have penalizing; please check the following points.
Before going to the main topic; we will emphasize again that please do not get panicked if you are losing traffic rapidly. It is a natural phenomenon that a website’s traffic from Google will increase and decrease, some what line upper part of the sine curve. Just keep posting a bit more frequently for few days; believe us, for 90% of you who are losing traffic will gain back. Another thing keep in mind, after a certain period (it is said by SEO experts to be around 5 years) a domain gets aged and Google position a bit lower. There are exceptions for few websites, practically we can forget about exceptions; only few remarkable websites in the World might be out of that thing.
Notice the graph after 23rd February.
Generally these are the factors which most SEO experts agree to be causes of Google’s penalty:
Link Farms: We wrote ago about link farms. Try to avoid posting majority of posts with external links as original source. Write in your own language or knowledge. It is generally agreed that link to Wikipedia, other online encyclopedia, dictionaries are not taken in to account. But yes, it is not good to copy all the posts from Wikipedia.
Cloaking: Principle of this technique is based on showing different content to human readers and search engine robots. So that what is being indexed in Google is different from what is shown on the blog. You might have an experience of searching with some keywords in Google search and landing to a different or content-less website.
Unfortunately, every human probably has few bad habits like to get more better traffic than he / she currently is getting and that too very rapidly. There are certain WordPress plugins which mechanism of action is some what on the black hat side. Try to be refrain from them. Features of them to identify are : they are not given for free, they almost gives guarantee to get a huge search engine traffic, not recognized by WordPress etc.
Disable it if you are using and have started losing traffic after initial traffic boom.
Mirror pages: Several pages that link to each another having the same content. The attempt is to trick the search engine bots a kind of making fool. Again there are such softwares and plugins. Manually it is impossible to create.
Doorway pages: This technique is to create pages optimized with keywords for positioning, but not understandable to humans. These pages are easy to crawl by search engines and it itself redirects the visitor to the actual page of content with a graphical button or some such method.
Hidden texts: It consists of hidden text and keywords on the page with the same color and that of background. Suppose, if we write SEO, Google, Penalize, Penalty etc keywords in white text color and place them at the end of the post, you can not see them. But, search engine bots will take them as rich of those keywords and position them higher. But, after a certain time, Google probably compares the color of the text and color of the background. As you can understand, the detection takes a bit time. But they are recognized and the whole domain is penalized.
Shadow domains: Misleading links from a few pages and positioned to other domains. This technique is commonly used by SEO companies but it is very dangerous because it may carry a penalty. Look carefully, we have pointed our other website in the author box clearly saying it is another domain. Google will read the texts before and after and will understand it is just an innocent way to let others know about our other website; there is nothing wrong.
But if we write here, look at this article for SEO techniques, and point it towards the post about a disease, that will be very bad. If you need to refer, clearly write in the anchor text that it is another website in some way, make it nofollow and do not do it more than 5 times per 2000 posts (as far we got as a general concentration from different forum discussions, however; we personally think it should be 1 or less per 1000 posts if the field is completely different). Google gets the WHOIS data officially. So they know are you a good boy or good girl.
Creating too much free domains to get backlinks: For testing you can obviously register two or three free WordPress or Blogger blogs. But if you create a domain for each posts (there are even such plugins and softwares which has big list of their fake free domains and puts backlinks randomly in an automated manner) you can guess it will be not good.
Spam links: This is mainly active in forums and signatures. For blogs, simple disallow from robots.text (you can use nofollow too, but Disallowing is better in our opinion).
Spamming with keywords in meta: Google does not gives value to Meta Name Keywords, but quickly identifies keyword spamming. Google, Googles, Gogle, Gooogle is an example set.
It is said there are hundreds of factors which Google considers. If you face such problem, you can ask directly in Google Webmaster Central.
If you have any question, feel free to discuss privately using the Contact Us form.