Why are Unique Pageviews less than Users?
I created a filter ga:previousPagePath=~pagesA;ga:pagePath=~pageB (where pagesA is actually a group of pages). The number of Unique Pageviews returned (68) was less than than the number of users (113). How?
Background and Detail:
I want to return (via API) the number of sessions where any page within a set of pages (pagesA) is followed (at any point) by page B.
Ultimately what I think I need is a segment which is set up as follows:
Filter: Include: Sessions Sequence Start: Any user interaction
STEP 1: Page matches regex pagesA
Is followed by
STEP 2: Page matches regex pageB
However, in trying to get my head around segments versus filters; and sessions/pages/unique pageviews etc, I ran a test to see what would happen if I compared the results of a similar segment (but with “immediately followed by”) with a filter that looks at previous page. I figured this was pretty much the same thing, but clearly not.
The results were mostly what I expected. Both methods returned the same number of users (113). The segment returned 114 sessions whereas the filter returned 0 (because none of the pages I’m looking at were landing pages). However, they differed vastly with the unique pageviews. The segment returned 541, which makes sense to me as it would count ALL pages visited in sessions that also included group A followed by B.
What didn’t make sense to me is why the filter method returned only 68 pageviews, which is less than the number of users. Can anyone explain this to me?
And whilst you’re at it can you also confirm that it is safe for me to use a segment that counts sessions in this situation, even though we’re using hit-level dimensions (pages) to filter them?