The document discusses tag management systems and how they operate in the stateless web environment. It notes that TMS inject JavaScript and act as message buses to update data models. While TMS were originally developed for non-technical marketers, they now serve both marketing and technical functions, including injecting tags and metadata, fixing code errors, and loading libraries. The document cautions against using TMS to fix underlying website issues and recommends proper integration with backend systems.

1. Rationalizing Tag Management
by Simo Ahava (NetBooster)
for MeasureCamp VI
”It’s just JavaScript” – William Henry Harrison

2. The web is inherently stateless.
Tag Management Systems operate
in the web.
Tag Management Systems are
inherently stateless.

3. it’s just JavaScript

5. Landing Page, Session, and previous touchpoints are
terminology of a stateful machine, not the web.

6. Landing Page, Session, and previous touchpoints are
terminology of a stateful machine, not the web.
The web feeds messages to a backend process, which builds
the data pipeline. Not the other way around.

7. Solutions
- Simple response mechanism for hits to Analytics
(GA requests are unilateral today)
{"newSession":"true", "sourceMedium":"google/cpc"}

8. Solutions
- Authentication of TMS, and real-time data written
in dataLayer

9. Solutions
- Forget it. Build a proper data pipeline server-
side and let the TMS do what it’s good for (sending
raw hit data to the backend).
^^^^^^^^^^^^^^^^^^^^^^^^
follow @carmenmardiros

10. dataLayer.
The confusing, intimidating,
developer-requiring, geek-nerdy,
ScravaJipty, structured-or-
arbitrary, perhaps-necessary,
damn-it-to-hell dataLayer.

11. it’s just JavaScript

12. It’s not generic
Native Array
GTM’s dataLayer

13. dataLayer != data model
{{dataLayer test}}
> undefined

14. dataLayer != data model
{{dataLayer test}}
> ”true”

15. dataLayer != data model
{{dataLayer test}}
> ”false”

16. dataLayer != data model
{{dataLayer test}}
> ???

17. dataLayer != data model
{{dataLayer test}}
> ”false”

18. dataLayer != data model
dataLayer is a message bus.

19. dataLayer != data model
dataLayer is a message bus.
The push() method is appended with a listener that
updates values in the data model as they are pushed
into the Array.

20. dataLayer != data model
dataLayer is a message bus.
The push() method is appended with a listener that
updates values in the data model as they are pushed
into the Array.
push() is the only method with significance. pop(),
split(), slice(), splice() etc. will not affect the
data in the data model.

21. dataLayer and developers
I will not demean myself to comment on this.

22. dataLayer and developers
I will not demean myself to comment on this.
OK, yes I will.

23. dataLayer and developers
I will not demean myself to comment on this.
OK, yes I will.
If you are working in digital
and you are allergic to
developer/IT cooperation, you
are in the wrong line of
business.

24. GTM and Google Analytics do not
have a special connection.
There is no special connection.

25. GTM and Google Analytics do not
have a special connection.
There is no special connection.
At the moment.

26. GTM and Google Analytics do not
have a special connection.
There is no special connection.
At the moment.
I’ve said too much.

27. it’s just JavaScript

28. What is Google Tag Manager
1. A JavaScript injector.

29. What is Google Tag Manager
1. A JavaScript injector.
Yeah... that’s it.

30. TMS is a marketer’s tool.
TMS is a developer’s tool.
TMS is a marketing-minded
developer’s tool.
TMS is a developer-minded
marketer’s tool.

31. it’s just JavaScript

32. Why it’s about marketing

33. Why it’s about marketing
1. ”Tags” collect data for marketing
attribution

34. Why it’s about marketing
1. ”Tags” collect data for marketing
attribution
2. Non-developers often got the code wrong
or didn’t understand variables -> TMS
was born to template the tagging process

35. Why it’s about marketing
1. ”Tags” collect data for marketing
attribution
2. Non-developers often got the code wrong
or didn’t understand variables -> TMS
was born to template the tagging process
3. Semantic information has been a mystery
to webmasters / developers strongly
immersed in presentational and
experiential layers (HTML+CSS+JS)

36. Why it’s about IT

37. Why it’s about IT
1. It’s a freaking JavaScript injector!

38. Why it’s about IT
1. It’s a freaking JavaScript injector!
2. You can add all sorts of malicious /
website-breaking / malware-infested code
with the click of a button

39. Why it’s about IT
1. It’s a freaking JavaScript injector!
2. You can add all sorts of malicious /
website-breaking / malware-infested code
with the click of a button
3. If When you need dataLayer, it needs to
be integrated to the systems which
expose the semantic information

40. Why it’s about IT
1. It’s a freaking JavaScript injector!
2. You can add all sorts of malicious /
website-breaking / malware-infested code
with the click of a button
3. If When you need dataLayer, it needs to
be integrated to the systems which
expose the semantic information
4. If something goes awry, IT will be held
responsible (as they own the processes)

41. Should a TMS be used to hack
around a poorly coded website?
<insert witty golf analogy that
explains why it’s not a good
idea to overcorrect faults or to
fix errors with errors>

42. Things you can do with a TMS

43. Things you can do with a TMS
pop-up dialogs

44. Things you can do with a TMS
pop-up dialogs
quick fixes to markup

45. Things you can do with a TMS
pop-up dialogs
quick fixes to markup
event.target.parentElement.parentElement.children[0].cousin[1].neighbor.dog
complex DOM traversal

46. Things you can do with a TMS
with a JavaScript-disabled browser

47. Things you can do with a TMS
with a JavaScript-disabled browser

48. Things you can do with a TMS
1.Proof-of-concept experiential & presentational
changes to get buy-in from IT / HiPPO

49. Things you can do with a TMS
1.Proof-of-concept experiential & presentational
changes to get buy-in from IT / HiPPO
2.Inject semantic information (JSON-LD, META
tags)

50. Things you can do with a TMS
1.Proof-of-concept experiential & presentational
changes to get buy-in from IT / HiPPO
2.Inject semantic information (JSON-LD, META
tags)
3.Fix glaring errors in conflicting JavaScript

51. Things you can do with a TMS
1.Proof-of-concept experiential & presentational
changes to get buy-in from IT / HiPPO
2.Inject semantic information (JSON-LD, META
tags)
3.Fix glaring errors in conflicting JavaScript
4.Load 3rd party libraries (e.g. jQuery)
asynchronously

52. Things you can do with a TMS
1.Proof-of-concept experiential & presentational
changes to get buy-in from IT / HiPPO
2.Inject semantic information (JSON-LD, META
tags)
3.Fix glaring errors in conflicting JavaScript
4.Load 3rd party libraries (e.g. jQuery)
asynchronously
5.Plus all the usual benefits (tagging,
consolidating code, arbitrary JavaScript /
HTML injection, etc.)

53. it’s just JavaScript

54. Favorite JS resources
http://www.codecademy.com/en/tracks/javascript

55. Favorite JS resources
Nicholas Zakas – Professional JavaScript for Web Developers

56. Favorite JS resources
Douglas Crockford – JavaScript: The Good Parts

57. Favorite JS resources
Cody Lindley – DOM Enlightenment

58. Favorite JS resources
http://eloquentjavascript.net

59. Favorite JS resources
Chrome (OS X) : ⌘ + ALT + J
Chrome (Win) : CTRL + SHIFT + J

60. THANK YOU
@SimoAhava
”The awesome splendor of the
universe is much easier to deal
with if you think of it as a
series of small chunks.”