Recently I noticed that when I export data from Analytics via an Automatic Interface that runs daily. The numbers I am seeing within the data downloaded vs the dashboard figures are completely off. When I’ve gone to Google Analytics and exported the same date range data as an Excel doc the numbers appear to match (near enough).
I couldn’t make any sense of this so decided to do a little research.
I managed to find a brief description of what could be happening;
This is because GA de-dupes the Users metric for the time period you're looking at. So if User A visits on 01/01/2018, and then again on on 01/02/2018, they show up in your daily table twice. But since they are just a single user, they only get counted once for the entire period grouped together.
Now… this got me thinking! How the heck can we go about turning this feature off…? I found the following;
You can't turn this off because it would conflict with the definition of a user -- if someone returns to the site multiple times, they're still a single user. If you want to see a metric that increments each time they return, you can use the sessions metric instead. Or you can create a custom report that shows users by day, just as you did above.
Sorry I couldn’t have been of any help but I hope this explains the way it’s working so you don’t have to go digging like I did!