Christian Oliveira has documented an issue with using Google AMP and how it will likely inflate your Google Analytics and other analytics metrics. In fact, it can report four-times more traffic than is real. Truth is, this was documented and Google recommended you set up its own profile for now to separate this out.
In any event, Google is aware of the issue and said it is complex but they do plan to work on it - one day.
Here is Google's Malte Ubl on this concern:
@bastanzio @christian_wilde this is essentially correct. Should be documented somewhere as a known issue.
— Malte Ubl (@cramforce) March 2, 2017
@christian_wilde @bastanzio yes, but not an easy fix.
— Malte Ubl (@cramforce) March 2, 2017
What is the outcome? This is how Christian summarized it:
- Unique visitors: as we have just checked, a user accessing from the same device, using the same browser and withouth deleting cookies, can be counted as up to 4 unique visitors depending on how he/she access our AMP pages.
- Sessions: if a user visits an AMP page, in any of the environments and leaves, there is no problem in terms of sessions. But, if he continue navigating our website, from the AMP page to any other non-AMP page on our website, apart from being counted as a new Unique Visitor, a new session is started, so it is counted as two sessions.
- Bounce rate: due to the previous reasons, when a session is divided in two, the first session would have only one pageview (so it will be counted as a bounce). The second session, if it only checks one page, would also be considered a bounce. So, the bounce rate will be increased incorrectly (the complete session should not be considered a bounce, but it ends being two bounce sessions). And this happens both for AMP and non-AMP pages.
- Pageviews per session: also in consequence of the previous reasons, instead of having 2 pageviews/session, we would have 1 pageview/session.
- Traffic sources: traffic coming from our AMP pages to our non-AMP pages from 3rd parties, will be counted as entry traffic (new sessions) and its source would be “Referral Traffic”, from cdn.ampproject.org (or yourwebsite.cdn.ampproject.org)
We have no idea when this will be resolved by Google, it has been an issue since Google launched AMP.
Forum discussion at Twitter.
