As you know we can set country that we target on webmaster tools I have a website and its TLD is .com and ip adres belongs to U.S.A however I'm targeting Turkey's visitor's should I set geo locations setting as Turkey or leave as it is ? does this make any difference?
Maybe it would helps a bit if you set geo locations setting in turkey, but I think there wouldn't be any big difference if you leave it as it is. You could still target visitors from turkey from using .com and I.P. from USA.
In geo targeting with geolocation software, the geolocation is based on geographical and other personal information that is provided by the visitor or others. so I think it may help you