Are customers the same all over the world or do culture and size of a country make a difference?

customers differ from each other because of the different needs ..desires ..habits ..traditions ..and culture as well as their financial conditions, so we find that a successful company is that the training and development of employees in the customer service department to deal with all types of customers, whatever the circumstances or attributes

Language and culture do affect the psychology of your customers and thus the way that you should be following in dealing with them.
An Arab, for example, wouldn't mind if you were considerate and asked about his health at the beginning of a phone conversation, while a German, on the other hand, would opt for a more straight to the point approach.

The type of customers are different in everywhere in the world , even in different cities in the same country .
Therefore we should deal with the cultures ,attitudes ,behaviors, languages , religions …etc , because some of the dealing which considered a kindly in X culture ,it is unkindly in Y culture.
So it's necessary to study the society's cultures to know the key of making them happy and avoid any miss-dealing with them.
All These don't mean that we don’t have a basics and standard of services , like the welcome words , smiles , fast service…etc.

I totally agree.
Customers have different need and expectations depending on nationalities so culture and habits.
They feel more comfortable to be followed and helped by Customer Agents or Supporter who understand them 100%.
Languages skills is a must when you are an Agent and work abroad and travels experiences all over many countries is a plus to be fully open minded.

For sure the customer negotiations skills is the same allover the world especially i can swear about the Arab Countries but it's different from country to the other according to them habits them income and how they think about the product

The different value of education of a country makes difference

They absolutely differ ..
from culture to culture & from country to country ..
but I don't think that the size of a country plays a role in this ..

Customers are same all around this is because each and every customer looked for quality in goods and services, frequency of supply, and we all need to get satisfied as customers but what differs the customers are the cultural backgrounds community beliefs habits financial status but as customers we are all look for the same thing quality, satisfaction and all that

The customers around the world are not the same and depends on which geographical zone customer you are dealing with.
For example there is a difference between Americans and Europeans.
Dealing with the American customers is much more easier and it is easy enough to sell them a product (or) making them understand on a resolution that you have provided, where as Europeans customers its hard to sell them a product (or) fixing an issue with an interim solution.
Americans will give you time to fix an issue then Europeans.
So if you have Europeans then be aware that you are giving them the best explanation and keeping it short, so that it impress him/her about the product and give a final resolution then talking about an interim solution that goes on and on...