Landing Pages Showing as Not Set in Google Analytics
Landing Page = (not set)
If you are seeing (not set) appear in your landing page report in Google Analytics it could be due to a number of reasons, but most often it's because a session has been recorded with an event level hit but no page views.
This can be due to a number of reasons and may be one of the following:
Incorrect Firing Rules
If a page view isn’t the first thing to fire when a page loads, or an event is the only thing to fire on a page because of an incorrect tag implementation, then a page view won’t be recorded and a (not set) landing page will appear. Check your ga('send', 'pageview'); appears first.
It’s possible that one of your filters could be filtering out specific page views for landing pages with events you are tracking. Check your view level filters!
This is one of the most common causes, especially on e-commerce sites offering a wide range of products or sites with lots of long-form content.
As some people tend to leave browser tabs open whilst they shop around for the best prices, or go and fetch a cup of tea from the kitchen, their session cookie may have expired by the time they return (if longer than 30 mins).
Their session has ended but they may trigger an event, such as viewing a video, resulting in a landing page of (not set) to be recorded alongside it. Similarly, a user could be visiting the site close to midnight – if the clock ticks past 00:00 hours then the session is ended.
Code Implementation Errors
Old on page code could be conflicting with your new Tag Manager code, or if you have an app the view you are using in Google Analytics might contain both the app data as well as web data!