I am considering starting to use Power Pivot. My reluctance is when I create an Excel Workbook using PowerPivot, does my audience also need to have powerpivot installed/enabled?
When you distribute your workbooks to others , will your workbooks have any Power Pivot related items in them ?
What versions of Excel will your users have ? Excel 2007 and older versions do not support Power Pivot , and so users with these versions of Excel cannot install Power Pivot , leave alone use it.
When you use Excel with Power Pivot , at least in Excel 2010 since I do not have any knowledge of Excel 2013 , Excel and Power Pivot have their own windows ; the data that Power Pivot uses is separate from the data which resides in Excel's worksheet tabs.
However , the whole idea of using Power Pivot is to crunch data and dervie reports , summaries. The normal end result of Power Pivot crunching data is a pivot table , which looks like a normal Excel pivot table , but is significantly different. See the following link for the differences :