The traffic data in this example has been removed on purpose, but general information used with permission from client.
One of the easiest ways to see if you are penalised by Google is to see how your traffic is doing. Here in this example that show things quite nicely. Here we are looking between February and April 2009.

example of a Google penalty
The client in question received a number of new links via some media attention, which was in turn picked up by some blogs. Initially the traffic grew to about 300% it’s base level, and then suddenly dropped off to about 5% of the traffic in the previous month. The remaining traffic was coming from other search engines, 3rd party site who linked to the client and direct type in traffic. Looking at the previous traffic , from the start of the year:

Jan 1st to Mar 10
We see that the traffic to the site was increasing steadily, it had some peaks and dips, in this case due to weekend traffic fluctuations, and then around February 26th there were two big jumps over 2 days. And then suddenly zero. So what happened ? Our guess is that because of the quick increase of the number of links to the site, that Google decided to over night cut off the traffic to it. This was also confirmed by seeing that the clients SERPs (Search Engine Ranking Positions) were also removed. The site: operator on Google was saying that the domain not in the index. For all of the other queries, where traffic was previously coming from, the client was no longer listed.
Our actions against the penalty
The client contacted us and gave us access to their Google analytics account, where we discovered that there was some strange things going on. When realising that they were no longer showing up within the first 5 pages for queries they normally ranked for and having no results from the site operator. We requested a reconsideration request on Google webmaster tools (click talk to Google on the right hand side, and then request reconsideration. Here we outlined what we thought had happened, and within about 2 weeks the traffic started to come back. We also took it as an opportunity to get some authoritative links from some business partners of the client, in order to add more trust to the domain. To enable faster spidering we also added a XML sitemap. This also helped to see if there were any problems indexing the content again. Note: When you send a reconsideration request you won’t hear back from Google, the only way you can find out if it was granted is if you start to see your site appearing in the index again.
Google on Reconsidering Request
Here is a quick video tutorial from Google on the topic of “Requesting reconsideration”
Further reading
Here are two good posts about the google penalties from SEOmoz.ORG and SearchEngineLand.com and are well worth a read.
4.20.2009
Hi Paul,
Nice post, would be interested to hear if this was on an old domain or a relatively new one. I’m pretty sure certain sites (within certain sectors) commonly receive influxes of incoming links when they launch a new bit of linkbait say – and / or that the site in question potentially was not that trusted by Google at time of the incoming links. Either that or this was not a common occurance within the sector that site operates.
If the link graph within the web for other similar sites differs vastly, could maybe have set a trigger?
Just like to know (if you can disclose)? the sector / age of domain?
Paul.
4.20.2009
Hi Paul, thanks for stopping by.
Domain is about 2 years old, but in the last year it has started to be pushed by the client. I don’t think the sector was the problem here, it wasn’t mortgage sales, credit card sales or medical related, for example. If it was in that market I would wonder about what you said alright.
I think it was the gaining of a significant number of links over a short period of time that triggered something. Plus I also don’t think it was that serious, because it was reversed so quickly. The site didn’t have paid links on it, or bought, but the number of links before the news coverage was minimal.
Paul
4.20.2009
nice example, thx. looks like a straightforward example of a penalty. one question, what was the bounce rate on the spike day? significant different? (i.e.: + 20%)?
br
franzseo
4.20.2009
Yes Franz, there was a spike on the bounce rate also over the 3 days, more like 25% .
4.21.2009
This is the frustrating thing about google and it’s a big concern – you can never get human to human contact. It’s extremely rare google will engage in discussion or disclose the reasons why they took the measures they took.
It’s like a one strike and you’re out policy – no warnings, no mentions of second chances… if a site is adding value to the internet (creating information), it surely deserves more respect from google and at least should get a warning or a second chance.
You’ve got it in this case (although they haven’t told you)… but imagine the number of people who are in a similar situation but don’t know what to do – google don’t exactly make it easy to contact them…
4.30.2009
[...] “An Example of Google Penalty” von Blackdog. [...]
5.1.2009
Hi Paul,
Interesting post.
When you say ‘I think it was the gaining of a significant number of links over a short period of time that triggered something’
What sort of numbers are you talking about and what timescale?
What type of sites and quality sites where the links on?
Was there anything on-site that could have triggered this?
This also raises a few issues, such as whether you could affect a competitor’s rankings if this was caused by offsite factors?
5.1.2009
Hi Michael thanks for popping by.
It’s hard to gauge the exact number of new links, but it was close to 200 (domains) over 2 days. There were some good links, but there was at least one spam blog syndicating network, which copied the authoritative articles and had bad quality links, as far as I could see.
The clients site hadn’t been changed since it was launched, roughly a year. The site looked generally okay.
Paul
5.2.2009
Did you push for the media attention?
What was your pitch to Google? (if you don’t mind me being nosy!)
BTW big improvement on the site. Nice clear layout.
Cheers,
Michael.
5.2.2009
Hi Michael ,
I don’t think if there was a push by us or not would be a factor.
For the reinclusion, I outlined exactly what had happened and what might be the reason why we were no longer in the index.
Paul
Glad you like the theme, I wanted something a little bit wider, and easier to read.
5.5.2009
[...] filled a few reinclusion requests. In fact I did a blog post 2 weeks ago about one An example of a Google Penalty | Search Engine Optimisation BlackDog __________________ my sites :irish poker / irish jobs / seo faq / advertise jobs free / green [...]
5.11.2009
[...] the weekend I came across some obviously bad SEO, which even has the potential to get the client a google penalty. This site clearly has had someone do some onpage SEO because nested in the footer, you can see the [...]
12.25.2009
[...] quick post to say thanks to my few clients who trusted me to get their website back in the index or to tweak their pages to get a few more visitors to their pages. Thanks to those who have [...]
1.13.2010
Google has many penalties. Google considers about hundrerds of factors to ban a site. You should get more details by involving here: http://www.google.com/support/forum/p/Webmasters?hl=en