Answer:
It is critical.
You will get a better understanding (outside of the scope of work) as to what the needs are.
You will gain a clear picture of how people use the data, expect to retrieve it, the current system limitations; from a user perspective.
How many times have you used software and said man this is good but I can't believe they did not think to include this or that, or this feature is hard to use, it would have been better like THIS.. Well that is YOU as an end user, and nobody bothered to consult you.
Now in a retail application they obviously can not ask EVERYONE and that is why they have user focus groups.
In a company however you can interview everyone or a good cross section of the users to determine there needs, put together a wish list / must have list by department. Then you can run a spreadsheet on this and start making decisions about version 1 feature sets, version 2, and so on.
THE CANDIDATE HAS LEARNED THE BEST PLACE TO HAVE RESUMES PRINTED