Item: Google Tag Manager
Rating: 9
Author: Chris Lenhart

Use Cases and Deployment Scope

Google tag manager (GTM) is a great way to handle all of the code snippets you need without having to bug your devs. It is also great for tracking custom interactions, again without needing to bug your developers to implement something and deploy. If you can write the JavaScript to find it on the page, GTM lets you measure it. It even allows you to set local and session storage variables to help you understand more complex user behavior.

Pros and Cons

Measuring custom interactions. If you know a bit of javascript, you can set yourself up to measure anything that happens client side on your site, no matter how complex the sequence.
Out of the Box triggers. Even if you aren't great at javascript, you can set up interactions pretty easily.
Independent deployment. You can create, manage, and deploy your tags yourself without waiting for your developers to deploy.

No retroactive measurements. If you haven't set up a measurement, there's no way to go back in time to find it.
Finicky javascript syntax. It can be picky about how it accepts scripts.
Interface changes a lot. It's usually an improvement, but it can make learning difficult because old tutorials quickly become obsolete.

Return on Investment

We have been able to conduct quantitative research based on very specific actions that would otherwise be drowned out.
We have been able to assign very specific metrics when evaluating feature performance.
We are able to trigger targeted email campaigns based on user actions.

Alternatives Considered

Heap and Pendo.io

Firstly, using GTM doesn't mean you can't use these other products if you choose. GTM is free, so there is no real "cost" to using it. The other products are meant for a slightly less technical audience, and they tend to do a better job of hand holding. The advantage for tag manager is that since it can be more difficult to a beginner, it can easily present its more powerful features to an experienced user. It is much easier to figure out how to trigger scripts in GTM than in the others.

Other Software Used

Hotjar, Heap, Visual Studio IDE, Marketo

Likelihood to Recommend

You should use Google tag manager if you have someone on your staff who has analytics and development chops, and you are interested in measuring interactions that go beyond simply what page was viewed or what button was clicked. If you need to handle retargeting ads specific to a particular interaction, or you want to measure interactions in a particular sequence over the course of a session, google tag manager is great.

If your organization lacks someone with these skills, look into a solution like Heap if you are small enough.

GTM - The most open and powerful analytics tool out there

Overall Satisfaction with Google Tag Manager