Google implements changes in the algorithm of the search engine often enough and just when these are updates that will have a huge impact on many websites, Google team launches an ad, as was the case with Google and Penguin. There are 2 types of “penalty”:
– penalties (shares), which directly affects your website, if you have resorted to such techniques as keyword stuffing, cloaking, backlinks overoptimization: in this case you realize pretty quickly because you will receive a message in webmaster tools.
– -algorithmic or automated penalties, applied in bulk: not getting notice, but the traffic and ranking drops drastically.
If your keyword position decreases very much (words that were in the first 2 pages are no longer present in the first 5 pages of Google results), traffic drops considerably (a decrease of at least 40%) and you have removed any on-page problem and seasonality, then more than likely the site was penalized/affected by the change in the algorithm. Usually right after announcing a major update (Panda, Penguin) the impact can be seen in traffic on Analytics.
But sometimes it’s hard to tell if a site is penalized, affected by algorithm updates (other factors matter/affect and your website has not kept up), exceeded by competitors or a traffic slumping due to seasonality. If you keep your keyword positions, but organic traffic is down, then it’s a matter of seasonality.
If your keyword positions are slumping and organic traffic is dropping, then it can be a problem on-page or your site has been affected by the algorithm updates. Attention, you must watch organic traffic (total traffic contributes to social media, direct traffic, adwords, newsletters, websites that make reference to your website … etc.). You should think at the promotional actions you have undertaken lately and the changes carried out onsite. Make sure that the site is properly indexed and that the information on the site is accessible to search engines. If you have performed linkbuilding, analyze the quality of backlinks. Techniques such as those below, can attract the penalty:
– Buying or selling links that pass PageRank (follow links).
– Excessive link exchanges.
– Publishing Advertorials and guest-posts in excess, with anchor text overoptimized.
– Automated programs or services to create backlinks to the site.
– Advertisements that pass PageRank (follow links).
– Web directories and sites of low-quality bookmarks type.
– Links in footer, templates or widgets distributed across many sites.
– Comments with links on blogs and forums in excess.
Sometimes, small actions such as the removal of some low quality backlinks and some improvements on-page, can bring a significant increase in organic traffic.
If the site is topped by the competition, you will see a small decrease in ranking. If you’ve not dealt with the site for months (you have not added new content on the site) is very likely to have been surpassed by competitors; possible situation especially for blogs and sites of presentation where timeliness and frequent updates of content matter to Google.
I recommend you to keep a monthly record of the main keywords and position to follow the evolution of organic traffic weekly. Compare traffic evolution with seasonality. And, of course, have inscribed your site in Google Webmaster Tools, to be aware of any problems that may occur.