Advantages of using Master Pages..

Answer:

1. You can make updates in one place as they allow you to centralize the common functionality of your pages.
2. With the help of Master pages, it is easy to create one set of controls and code and apply the results to a set of pages.
For example, you can use controls on the master page to create a menu that applies to all pages.
3. They are used to give you fine-grained control over the layout of the final page by allowing you to control how the placeholder controls are rendered.
4. You can provide an object model which allows you to customize the master page from individual content pages.