A great new whitepaper by my colleague Mariano Teixeira Neto:
The purpose of PowerPivot for SharePoint is to allow users to share their PowerPivot workbooks in a secure and scalable environment. To ensure that you are sharing and collaborating on the most recent data available to you, PowerPivot for SharePoint provides a data refresh feature that lets you automatically update PowerPivot data in an Excel workbook. This white paper describes in detail the data refresh feature in PowerPivot for SharePoint. It starts by explaining the steps for setting up a data refresh schedule in SharePoint, and then it continues with an in-depth view on how data refresh works on a SharePoint farm. Both administrators and the business analysts who author and manage PowerPivot workbook data can benefit from learning more about setting up and using data refresh in a SharePoint environment.
Download the entire whitepaper here.