Misunderstood Metrics: Sessions for Pages

Build a custom report to see how many Sessions included your top pages, and the result is confusing! Chances are you will see the number of Sessions drops sharply once you get below your primary landing pages. What gives? How can the number of Sessions be lower than the number of Users? Doesn’t every user have at least 1 session?

sessions-for-pages

Blame it on Google. They made it really easy for you to build the report and didn’t warn you. The problem is that the Sessions metrics should not be used with Hit-level dimensions like Page, but Google doesn’t tell you that. They also don’t tell you what a Hit-level dimension is, and there is no simple way to figure it out. The standard reports are fine, but that Second Dimension button can be dangerous!

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Why? Why? Why?

sessions-for-pages-detailHere’s the reason: Google tags the Session count only to the first page viewed in a session — i.e. the Landing Page. Lets look in detail at a single session and how Google records various metrics page-by-page through it.

The image contains two sections – at the top, an extract of the detailed page-level metrics from the API (displayed in an Excel worksheet); and at the bottom, a copy of the Google Analytics All Pages report for the same session [click the image to see a larger version].

See your own website data: Misunderstood-Metrics-Sessions-Pages.xlsx and refresh with Analytics Edge Simply Free

You can see that while there were 13 page views in total, only 7 different pages were seen (unique page views). A Pageview is counted for each page, an Entrance is recorded for the first page and an Exit was recorded for the last page. Unique Pageviews are counted only for the first visit to each unique page. Nothing unexpected there. The totals all match the standard report.

BIG SURPRISE: the Sessions are counted ONLY for the first page!

This is why you shouldn’t use Sessions when you report at the Page-level. Why would Google do this? You might think:  well, there is only one session here and they count the session only once, and that is so that when you total all the metrics in the report, the total should be 1. They assign the Session count to the first page in the session, and that sort of makes sense.

A good rationale, and that might have been true once upon a time, but if that is the way things are, then why are the Users shown as 1 for every page view? That would total to 13 Users. Inconsistencies like this breed confusion for new and casual users.

You might notice that New Users also gets counted only for the first page viewed, and you might wonder if Sessions is the same as New Users, but it isn’t — the example I used just happen to be for a new user to the site. In fact, the Sessions metric reflects the Entrances for the page [there are a few cases where these will differ slightly, but let’s not get into that now].

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How to Report Sessions for a Page?

If you want to see how many sessions included each page, then you need to look at the Unique Pageviews metric on the All Pages report. As we showed above, this metric is counted only once for each page in a session, so it really reflects the number of sessions in which the page was viewed. I suggest you change the metric title before you send the numbers to someone else or you will have to explain everything…

Bottom line: Do NOT use Sessions in a report with Pages! Use Unique Pageviews instead. Tweet this!

Discover The Entire Google Analytics Misunderstood Metrics Series:
Next Page Path,  Sessions for Pages,  Events,  Unique Events,  Custom Dimensions,  Count of Sessions, Time on Page/Session Duration

Comments: (moderated, no spam)

  1. johnnybegood

    I’m still bewildered by some of this Google Analytics logic.

    We have a destination goal. Say, a “thank you” page once a user submits a contact. I have set up a goal for this for quite some time.

    The goal will say 29,000 people have completed the goal in November, for instance (reached the ‘thank you’ page).

    The pageviews of course will say 37,000 hits were made to the thank you page. Odd, but I guess some people may hit refresh/ the back button and reach it again, okay. No harm, no foul.

    Here’s the tricky part. I use ‘unique pageviews’ which you said counts each unique page once per session – set up the destination exactly the same as the goal destination … and 31,000 unique hits were applied to the thank you page. Why is this one different? The unique is AT MOST once per session. Why would it be counting more than the actual goal?

    I’m wondering because I’m trying to get past data for some ‘destination pages’ before I set up goals for them. But there appears to be nothing in Google Analytics that replicated the ‘destination page goal’ number in the past.

    Reply
    1. mike_sullivan

      Make sure your time period does not trigger sampling (>500,000 sessions in total for the period, and you have the slider all the way over to most accurate instead of faster). Goals are greatly affected by sampling. Try a shorter time period to see if the problem still exists.

      Reply
  2. Ed

    How should the ‘Unique Views’ metric be used when using content grouping, sis this the best metric? Basically I want to count up how many sessions included a visit to at least one page in my content group segments? This is so I can gauge the % of visits to each section. Any clarification appreciated

    Reply
    1. mike_sullivan

      Yes, then Unique Views metric should be used like Unique Pageviews when you are working with Content Page Groups

      Reply
  3. Akhan

    Thanks, Mike!

    Can you please explain what you meant by “if there is no pageview (or other indicator in the event category, label or action) sent with the event, then the event hit may be all you get.”

    I looked at the Events section and found some Events which show up with the ‘not set’ label. Can they relate to your example scenario and could possibly be the reason? http://screencast.com/t/08Uyq2N3

    Reply
    1. mike_sullivan

      You are seeing a different scenario – there is no value for the Event Label. The reason — you didn’t send one in your Javascript snippet?

      Reply
  4. Akhan

    Thanks, Mike,

    That explains it all. So, I was having a wrong perspective about the Pageviews. One more question and would much appreciate your help in understanding it better, as well.

    I’ve created a custom landing page report where I set source/medium to Google/organic. As I look through the landing page URLs, the large portion of traffic is marked as ‘not set’ under sessions while the same is showing ‘0’ under entrances. I read Google docs about not set and I barely understood anything. What could be possibly causing my organic landing page report to be vague because there’s a large portion of traffic without URL specified?

    Thanks again for taking your time to help me!

    Reply
    1. mike_sullivan

      If you use events on your landing pages, it is possible that the event is firing before the pageview, causing the session to start with the event. That makes the landing page for the sessions to be (not set). Since the session ‘1’ count is associated with the event, which does not appear in a pages report, the sessions are ‘0’.

      Reply
      1. Akhan

        Thanks so much!

        If I’m not wrong, the (not set) shows 100 sessions and 0 entrances. It’s because these pages triggered an event or events first before page hit can be recorded? Is that even possible to know what that event is and what pages triggered that event?

      2. mike_sullivan

        Scenario: person reading your site on the bus. Gets to work, makes a coffee, settles at their desk, and then looks at the article, clicking something that triggers the event. More than 30 minutes since the last interaction, so Google Analytics sees it as a new session; if there is no pageview (or other indicator in the event category, label or action) sent with the event, then the event hit may be all you get.

  5. Akhan

    Hey, thanks!

    So, from the organic landing page perspective, should I use sessions or entrance or unique pageviews as the primary metric? Also, why GA is showing so much difference between unique pageviews and entrances when I’m on all page report? Even if each entrance is considered as unique pageviews, the total number of entrance should at least match with the total number of unique pageviews, right? But it my case, the entrance for a URL is showing as 2000 while the unique pageviews is 20000.

    Can you please help me understand them better? Thanks!

    Reply
    1. mike_sullivan

      A report with Page and Unique Pageviews shows the number of sessions that included a view of that page.

      A report with Page and Entrances shows the number of sessions where the page was the landing page (the first page viewed).

      If 2,000 people visited your site and viewed 10 pages each, the total entrances would be 2,000, and the total unique pageviews would be 20,000 (10 x 2,000).

      Reply
      1. Akhan

        Thanks for replying!

        I’m just confused about the last statement. When I a create a page level report, isn’t it all the metrics in the report pertaining to the page in question?
        example.com/somepage.aspx GA Entrance – 2000 GA Unique Pageviews – 20000

        I was under the impression that there was 2000 entrance to the above page from Google search and the same page got 20000 Pageviews. It looks like I was wrong throughout.

        Thanks for helping me out!

      2. mike_sullivan

        A different example to clarify: if a single visitor hit your site on page A and then viewed page B.

        Page A = 1 entrance and 1 unique pageview (1 session included the page)
        Page B = 0 entrance and 1 unique pageview (1 session included the page)
        TOTAL = 1 entrance and 2 unique pageviews

        So page B had 1 unique pagview even though it had 0 entrances because the pageview was NOT the first page viewed during the session. This is how pages can, and do, have more unique pageviews than entrances, especially pages that are not common landing pages. For any individual page (NOT the total), the number of unique pageviews equals the number of sessions that included that specific page.

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