It All Started With An Idea

How to Scale 15,000 Google Analytics Properties via GTM

Dilemma:

I am one person. Google does not automate GAUIDs, Google provides wonderful tools that depending on what “Scale” means to you. That are not very efficient at “Scale”! Back to my dilemma:

-4750 UAIDs

-Generate, Placement, Publish each one of these pixels/tags across 4,750 sites

-All one-by-one

-I am the only person working on this ask

It Was Easy Until:

At no point was this task easy, to manually generate 4750 Google Analytics IDs was time consuming. I estimate total hours spent to be about 32Hrs, give or take a stand-up break or two.

To generate a UID is fairly simply – (the process)                                                                                                                                           

-Create a google analytics accounts or login if you already have one (google.com/analytics)

-Locate your Admin widget, bottom left hand corner of UI

-Create an account (first issue I ran into, is that I have a free account, yes that is correct. Another conversation for another day)

Free is an issue, because you are only allowed 100 accounts, with 50 properties

Remember we are a global entity, managing global OEMs, yes this is new for us, however not for me and since I have a free account. Yep you got it I needed more accounts. Luckily, we have a pretty good relationship with Google, so thank you Google for granting me another 100 free accounts. (promise 360 is on the list of to do’s)

When you create an account, you are creating your 1st property (not going to get to deep into the weeds here). The only way to effectively scale this is one of 3 ways. Click, Click, click by yourself and copy past URLs and whatever nomenclature you want for each property and account. Standardization is recommended so you might want to use sheets, or excel to build out what your GA might look like. 2nd have a partner or partners (to which I did not have) or 3rd, come up with some automated script that can read multiple screens and replicate the process, like an excel macro. 

The Hard Part Is Over:

-Created 107 Accounts

-50 Properties under each account

That’s over 5,000 manually generated UAIDs

Now the Fun Begins:

Tools I recommend, okay devs and engineers give me a break!

-Chrome or Firefox (I haven’t used windows explorer since Freshman year in college) Love you Microsoft!

-Learn to use Dev Tools hit F12 (explore its fun, lots of interesting things you can do with a site, to a site from this perspective) Example like deleting those nasty pop-up membership forms.

My FAVs ^^^^, if you don’t know what these are, get them, study them, use them. 

1st – Page Analytics

2nd – UET (Bing)

3rd – Tag Assistant

Each one of these are for your browser

-You also need GTM

-You need a handy script

-A developer or access to your Master Site or Site(s)

-Excel

-Google Sheets

Good you have your tools. If you do not go get them.

The Basics are Over: Here is how I scaled this puppy out.

 –1st I did it manually yep all 4K plus UAIDs, copy and pasted into an excel spreadsheet. You always want to keep a record/journal that can be transferred to confluence, one note etc. (tribal knowledge is bad knowledge)

-2nd I decided to spend 3 weeks plus or minus another week or two, manually loading these into GTM. I created a lookup table via a variable.

4 thousand rows later, 8 thousand total copy and paste form fields later. My container size was too big. Wonk, Wonk, Wonk lol. 

I just found out it was not possible to scale this, Google’s unlimited open source Tag Management system had limits. 200kb to be exact. Roughly 1750 rows (plus or minus a few) for each container. I have six now.

So Just to Let You Know I Am Not Copy and Pasting Again forget it

Options:

Outsource to a team

Get Interns

Do it yourself

Or while your friend @MitchLarson is working with you on scaling Price Extensions via BigQuery and you are becoming more comfortable with scripts. Think of a way to automate, exchange data between excel and your web browser. Sorry Mitch. I definitely owe you a food truck lunch at Hero Conf in Austin.

Here is how you effectively scale, utilizing resources at hand. Saving time, money, fingers, mouse and keyboard. 

Step 1:

Open up your EXCEL or Goog Sheets w/ your hundreds or thousands of rows of UAIDs & domains

Step 2:

Log into GTM, open up your container and go to your variable where your look up table sits

Step 3:

Hit F12 on your keyboard in the window that your GTM container and variable are open in

Step 4: Find console in dev tools, will vary by browser. Firefox is at bottom, Chrome is Upper right as seen below

Step 5:

Use this link: https://docs.google.com/spreadsheets/d/1-iZ9GxVgAUoaEDl2wlBDrGG0c9NIKUAKjrte_msI2H0/edit#gid=0

Thank you LunaMetrics team

Step 6: Once you have completed this sheet, you will copy the 5 column all data and rows and paste into the console section of your open browser

Should look like this:

Hit Enter to Execute the Code in the browser and Yep you now have automatically generated 4500 + rows into your GTM container.

 Lesson I learned, it is okay to do it the hard way. Without first understanding what is possible, I might not have thought of the things that were not possible “initially”. It did take up a bit of my time, maybe more than my leadership might have wanted. However, in the end, I was able to clean up and create my containers in minutes. Most importantly I learned something new. That is now able to be passed along to peers, teammates and anyone else in need of quickly scaling google analytics across their sites.

About the author

John M. Williams — Founder, It All Started With An Idea. Senior paid media specialist with 15+ years and $350M+ in managed ad spend across Google, Meta, LinkedIn, and Amazon. Creator of Buddy, the open-source AI Google Ads agent. Hero Conf 2025 + 2026 speaker.

More about John · LinkedIn ↗ · GitHub ↗

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