Multiple data sources, multiple uses for the data from each source.
Suppose you run the human resources department of a medium-sized company. Your staff sees lots of resumés, usually in the form of documents or e-mail messages.
Wouldn't it be great if you could automatically copy the names, addresses, and lists of job skills from those resumés? And even better, if you could use your computers to match those skills with open positions? And best of all, if the same process prepared a report on your department's performance for your manager?
You can do those things (and more) with XML. You can extract data from various original sources, store that data in one place so you know just where to find it, and use the data again whenever and wherever you need it.
For example, do you need to report budget data for the past three years? However you store that data, if it's in XML, you can select what you need and import it into a document, worksheet, or database — whatever the situation requires.