It is important that you could centralized managing your global business. This will allow you to make decisions in a corporate vantage point. Without centralization, the decision will come from a country specific view which is sometimes vague. If your local knowledge is not essential for success and product customization needs are low, then centralization is effective for your global business.
When we say centralization, it is the process of centralizing your management, distribution and marketing efforts. You are using a single location to implement these things. This will lead to a unified approach and good coordination when it comes to decision making.
You can hire or outsource from one region and assign duties and responsibilities based on their location. You can have a marketing team in your headquarters and you can coordinate with your regional marketing personnel, they should be responsible of distributing your materials in their own respective local markets. You have centralized the production of your materials, so it is easy for you to manage the distribution to local markets in each region.