There are rules about how dimensions can be combined in 2-D reports. The rules have to do with the important distinctions between hit dimensions and visit dimensions.
A visit-based dimension applies to the whole visit – things that never change during the visit. The referrer does not change. The browser does not change. And so on.
A hit-based dimension can change from hit to hit. The URL changes. The day of the week can change.
In two-dimension custom reports, the first dimension must be broader than the second.
Visit is broader than hit. Hit is finer-grained than visit.
So you can use these combinations of Primary > Secondary dimensions in a custom report:
Visit > Visit
Visit > Hit
Hit > Hit
And you must NEVER use this combo:
Hit > Visit
For the latter, you will get a report with results, but it will freeze your soul if you look at it too closely, and astute consumers of your data will laugh at you, or worse.
For Hit-Hit 2D reports, both events must happen in the same hit!
Of course, Rule 1 begs the question of what is a hit-based dimension and what is a visit-based dimension. It’s not always intuitive and it’s definitely not in the UI or as far as I can tell in the documentation. Here’s the correct list for all the currently available Dimension choices and how WebTrends categorizes them. Pay attention, because you’d probably guess wrong on some.
day of week
hour of day
any custom drilldown
query parameter (when collected on “all hits” or “hits that match xxx” or “most recent value”)
query string (when collected on “all hits” or “hits that match xxx” or “most recent value”)
referrer (labeled “per hit”)
url with parameters
- ad campaign
new vs returning
query parameter (when collected on “first occurrence” or “last occurrence” )
query string (when collected on “first occurrence” or “last occurrence” )
referring page (the one labeled “initial per visit”)
referring top level domain
top level domain
visitor segment (WT.seg and WT.vhseg)