Hello Tad,
1. We are always getting a blank report on "Long Fat". If I understand this correctly this is traffic that is within top 1M of Alexa but not in the top 10%. We are a fairly large network so should this be blank?
Yes it is unusual but entirely possible that you have no traffic in long fat counter group. This is actually a mix of Alexa and Quantcast top 1M hosts. Long Fat hosts are those that are present in this list but not in the top 10%. Do you have reports in the Long Thin group (those that are not in the lists at all?)
2. Is there a way to *only* show the "diff" in the long tail reports?
The PDF reports have a diff between two days. There is a page that shows long tail hosts that appeared today that was not there yesterday. I think this is what you might be looking for.
Yes, please send across the PDF report.