26/06/2023 by Daniel Wigley
Google Analytics 4 VS Google Analytics 3 - key metric changes
On 1st July Google Analytics 4 will be the web analytics choice of many businesses with GA3 being deprecated. Since 2015 everyone has got used to 'staple' metrics to understand performance. These are sessions, users, bounce rate and last click attribution.
Just when everyone felt comfortable GA4 has now changed all of these metrics...
We've tried to give a simple explanation of each of the changes to try and make your life a lot easier
Sessions are changing
Normally you’d see sessions higher in GA3 vs GA4
⭐ There will be ‘overinflated’ traffic sources in GA3 vs GA4. In GA3 it pins the traffic source to however the session started. So… if a session starts from a click on a PPC ad and then in that same session renters the site using a voucher code website GA3 = 2 sessions, GA 4 = 1 session.
⭐ But.. the traffic source in GA 4 will be allocated to the PPC ad as this will be pinned to the ‘session start’ traffic source.
⭐ Also the funky ‘restart a session if it crosses over midnight is now gone (that’ll be small volume most likely!)
Users are changing to active users
Normally you’d see 'users' higher in GA3 vs GA4
⭐ Active users is basically users that don’t leave you site after an interaction (I think it’s easier to see these as non-bouncing users really..).
⭐ Google is now applying ‘engaged sessions’ to users to generate active users. Engaged sessions means they’ve triggered an event on your website (ie scrolled etc, etc)
⭐ These will naturally record lower as the active user is only counted if they trigger an event vs being counted by default in GA3.
⭐ Also.. If user ID functionality is enabled this will also count multiple ‘users’ as one and dedupe in your interface reports.
Bounce rate doesn’t exist – it’s engagement rate
⭐ Essentially ‘current’ bounce rate in GA3 is percentage of sessions that leave your site without doing anything else. So, bounce rate = single-page sessions / total sessions.
⭐ Whereas GA4 essential flips the metric on its head with ‘engaged sessions’
⭐ An engaged session is triggered by the visit lasting 10 seconds or longer (this can be changed to 60 seconds if needed), triggering a conversion event (assuming these are set up) or consuming 2 or more pages.
⭐ So, engagement rate = engaged sessions / total sessions. In short engagement rate is the inverse of bounce rate (IE % of those who interact vs those who leave)
⭐ So using this simple example should make it clearer.. 10 users visit your site. 5 of them leave without clicking on anything^ and 5 of them click onto another page. GA 3 bounce rate = 50%, GA 4 engagement rate = 100%
^if they spend more than 10 seconds on the site
⭐ GA4 is Data Driven attribution by default and not last click
⭐ DDA is an algorithmic model that takes into account each of the touchpoints observed for your website conversion events. It then does some modelling to assign credit to each channel.
⭐ GA4 collects up to 50+ touchpoints, ensuring that all of your marketing efforts are taken into account when assigning credit.
⭐ So in your reports you're likely to see conversions like 1,456.67 transactions for paid search as it takes all the data and credits it to the channels that drove conversion.
⭐ This is likely to make nutoriusly focused last click channels like affialites decline in credit and upper funnel like display get more credit
So in summary...
⭐Sessions should go down
⭐users should go down
⭐it's a new metric to understand page and traffic performance (engagement rate)\
⭐Attribution is not last click
Hope this helps!