Google on their web site say there is almost nothing you can do to harm a website through the building of links from external sites. I unfortunately came across the reason they say almost recently.
To a major extent they are right, even links from bad neighbourhoods will not harm you. The logic of course is that if this was the case it would be open season on all your competitors site.
However, with enough links from local language sites you can blow a site of the water!
We found this out accidentally. The background is as follows.
Google chooses the language of the site through 4 main factors. The physical location of the webserver (IP number), the top level domain name – “.de” for instance, the meta language tag(s), where the incoming links come from and also the actual language of the text.
Normally, you would think one of these factors could not override the rest. However, inbound links can override all other factors into duping Google that the page is of a different language than it actually is. This has disastrous consequences, for example if a German page focusing on German language readers gets a highly disproportionate amount of links from english language sites. Google ignores the fact the server is in Germany, the top level domain is “.de”, the meta language tag is “de” and considers the site english – which results in dropping a lot in google.de but rising in Google.com.
You know this is a problem when you see on a Google.de search the words “Diese Seite Übersetzen” which translated means “translate this page”. This normally corresponds with a fall in Google.de but a big rise in Google.com as Google does boost local sites of the language. I know this is a problem as it has happened to ourselves. http://www.abakus-internet-marketing.de/foren/ is a German language forum but was classed as english as I built too many links to it from non-english sites to it (easier for me as I am english). We quickly changed that and now things are back to normal. For a few days, a lot of traffic was lost. It also happened to a client before we knew about the existence of the problem.
The examples above were due to too many links from english sites, however, an English site with a too large ratio of say German links is likely to end up drastically losing rankings and having “translate this page” in the Google results.
If you come across an english language page with “translate this page” in the google reults and it fails to rank well then it will most likely mean you have too many links from foreign websites. This can happen through link purchase or through one of the many link networks for example.
Fortunately we have managed to get our rankings for our own forum and clients back. It took a while to figure the problem out though so I thought I would share it here. Clearly this can also be abused by knocking the competition ou,t so imo Google should really not just take inbound links as an overiding factor of language.
ABAKUS Internet Marketing