The problem may arise when a person owns a .com domain. Google doesn’t automatically know (from the extension) what geographic area you are targeting, and thus won’t know which localised search engine to give you preference in. In a case like this, Google will automatically assume you have no preference, and place dominance in the country that you host in. Fair enough, since you are most likely going to host a site in the country that you service most. But, what happens when you host your .com domain in one country and primarily do business in another? Well this is where the domain geo-targeting tool offered by Webmaster Tools comes into play.
If you want to set the geographic location targeting for a non-ccTLD (non country code top level domain) such as .com or .biz:
1. Login to your webmaster tools account at http://www.google.co.za/intl/en/webmasters/
2. Click “Site Configuration” in the left menu
3. Then click “Settings” beneath that
4. Under the “General settings” tab, you wioll see a “Geographic target” line. If your domain is a country specific domain (such as .co.za) it will automatically target that country. If it is not country specific (non-ccTLD) then you can stipulate there which country you want to target.
5. Choose your country
6. Click save
The setting will be updated immediately, but as we all know, Google can take a few days to take the settings into account. This will help you focus and rank in the country of choice.
If your non-ccTLD domain ranks well in the country you host in, but badly in the country you want top target, after making the above changes you WILL see dramatic changes in your rankings within a week.
Domain Geo-Targeting using Webmaster Tools

