IMHO a macro can be used in two main ways:
1) automate repetitive tasks (ie every time you open a workbook, you sort /
subtotal / print / clear subtotals .. making a macro perform these tasks in
this order will save you a lot of time)
2) extend the functionality of excel .... have a look at
microsoft.public.excel.programming for some ideas on what people are doing
with macros in this regard.
As to whether or not you need them - well, if you have repetitive tasks or
would like to automate a series of interrelated tasks - then yes, they will
help.
Cheers
JulieD
