Google Tag Manager is, essentially a manager for JavaScript, which means that you can use it to modify and enhance your website - sometimes to test sometimes when you have a CMS that can't do something as simple as a YouTube embed. Also, because of this, understand the risks.

1. GTM
Seriously awesome, but
seriously dangerous
Gerry White
Gerry@takeitoffline.co.uk
@dergal
With great power, comes great responsibility ….

2. I’ve got around – with 17 years in the business …
Yes – I am that old

3. Just Eat UK vs Deliveroo & HungryHouse … that’s all
me.

4. What is GTM and
what else can it
do …

5. for JS insertion ….
Variables
• URL, JavaScript, dataLayers,
Triggers
• Page Loads, clicks and interactions
Tags
• JavaScript to fire (some templated such
as GA)

7. Some real life hacks …

8. Norman doors at work
Fixed – with a post it
(two, one for the other side)

9. (the post it fell
off & got
quickly
replaced)

10. The Conti CC100
Coffee Machine
Amazing.

11. Our branded Mugs
don’t fit under the
coffee pouring
nozzels … 2mm!

12. Fixed – by turning
the metal grate
upside down …

13. So digital hacks…
(particularly SEO)

14. Ooh look
they have
GTM
installed to
manage
analytics

15. So GTM
& what can it do

16. Konami Code
Animated
Dinosaur!!!

17. Links!!

18. zurb.com/playground/jquery-raptorize

20. Check it out on
• Sitevisibility.co.uk
• TakeItOffline.co.uk
• SimoAhava.com
Sadly removed from some other sites …
& they’ve not let me do it to Just Eat
yet…

21. So how can I use it….

22. for JS insertion ….
Variables
• URL, JavaScript, dataLayers,
Triggers
• Page Loads, clicks and interactions
Tags
• JavaScript to fire (some templated such
as GA)

29. Auto internal linking
for hub pages
• Replace “ London “
• <a href='/london/’> London
</a>
But JS internal links won’t help
SEO will it ?

30. Name tags, triggers & variables
for use and re-use.
CJS = Custom JS, use folders and modify or remove expired.

32. We couldn’t easily let people
embed scripts into wordpress
blog posts but we wanted a
“juicer.io” feed of event
imagery
Doing it “properly” would
have taken weeks we wanted
it at the last minute…

36. • Tell visitors clearly that the page they're looking for can't be
found. Use language that is friendly and inviting.
• Make sure your 404 page uses the same look and feel
(including navigation) as the rest of your site.
• Consider adding links to your most popular articles or posts, as
well as a link to your site's home page.
• Think about providing a way for users to report a broken link.

38. Users don’t know or
care what a 404 is
& unhappy robot?

39. It goes without saying,
don’t put a clown on
fire on your error page
….

45. 404
Steps ….
1. Add in navigation
2. Add in some nice user friendly text
3. Minimise the geekiness (404)
4. Add in common links
5. Add in a search box (see what people type
in)
6. Customised according to URL
7. Monitor the conversion rate using custom
page
(custom groupings in Google analytics)
8. Monitor the popular 404s and fix

46. for JS insertion ….
Variables
• Page Title
Triggers
• Page Title = Page Not Found
Tags
• JavaScript - Add some navigation to the
page

47. Test with GTM

48. Triggers based
on scraping, can
often fail …
If they change the title tag,
the trigger stops working.
The solution is dataLayers

49. … dataLayers?

53. Scraping without
dataLayers

56. TIP- Use the preview mode!!

58. Edit metadata.

59. Bulk fix
title tags

60. document.title = 'SEO Friendly Title Tag';

62. webmasters.googleblog.com/2014/05/understanding-web-pages-better.html

64. test title
tags?

65. Fitting | Type | Brand
Type | Fitting | Brand | Dimmable
What is best for selling
lightbulbs

66. 1. Split your products in two groups
2. Modify the title tags in group 1
3. Test using GA
4. Wait …. Ages!

67. Splitting the groups
var x = {{dl Product.Sku}}';
var y = x.charAt(z));
Last character into a Custom
Dimension (product & hit level)

68. Data -
•GA –
•Entrances
•Non-bounce,
• conversions
•GSC –
•Rankings,
•impressions and
•CTR
Why did group A outperform group B – was it from CTR, Rankings, was
there an outlier in the group…. Use stats to ensure you are confident
about your results.

69. Implement these
title tags will give
us £xxx more per
month

70. JSON – LD
JavaScript Object Notation for Linked Data
(basically Schema.org)

78. TIP - gtmtools.com !!

80. "potentialAction": [{
"@type": "SearchAction",
"target": "https://www.yoursite.com/search?q={search_term_string}",
"query-input": "required name=search_term_string"
}

81. "potentialAction": [{
"@type": "SearchAction",
"target": "https://www.yoursite.com/search?q={search_term_string}&
utm_source=google&utm_medium=organic&utm_campaign=searchbox&utm_term={
search_term_string}
",
"query-input": "required name=search_term_string"
}

82. A crawl issue
Imagine an ecommerce website listed EVERY
product by every city

83. So … one part of the site ….
• Lots and lots of “DUST”
• What if there was a way to … I don’t know magically insert an
appropriate canonical tag… and see the impact?

84. https://moz.com/blog/
heres-how-to-generate-and-insert-rel-canonical-with-google-tag-manager

85. Speed up Sites?

86. Tip from @HoloMarkeD – who takes it to the next level -
http://code.markedmondson.me/predictClickOpenCPU/supercharge.html

87. <script>
var relPreRender = document.createElement ("link");
relPreRender.setAttribute("rel", "prerender");
relPreRender.setAttribute("href","https://www.yoursite.com/nextpage");
document.getElementsByTagName("head")[0].appendChild(relPreRender);
</script>

88. <script>
var relPreRender = document.createElement ("link");
relPreRender.setAttribute("rel", "prerender");
relPreRender.setAttribute("href","{{nextpage}}");
document.getElementsByTagName("head")[0].appendChild(relPreRender);
</script>

90. #product-actions > div.oos.oos-no-alt.border.space-b

92. for JS insertion ….
Variables
• StockStatus
Triggers
• StockStatus = Out of Stock
Tags
• JavaScript – Message to users and display
alternative products in LightBox

93. GDPR – you must lock
down your site.

94. GDPR hits in
2018 -
The right to be informed
The right of access
The right to rectification
The right to erasure
The right to restrict processing
The right to data portability
The right to object
Rights related to automated
decision making and profiling

95. GDPR hits in
2018 -
Manage & Protect users
data correctly or be fined
loads!!!
Fines upto €20m or 4% of
annual worldwide turnover,
whichever is greater

96. Konami Code Animated
Dinosaur!!!
If you can track the keystrokes for
the Konami code, think about the
impact for putting other peoples
JS on your site

97. Be really REALLY
careful who has
publish access

99. Someone scraped our French
site… & put on adult links … but
they didn’t change our GTM acc….
Easily no indexed.

100. Inserting JSON LD into a page
1. Organisation / site search
2. Ecom (reviews & product)
3. BreadCrumbs
4. OrderAction

101. Inserting JSON LD into a page
1. Organisation / site search
2. Ecom (reviews & product)
3. BreadCrumbs
4. OrderAction
Editing the page
1. 404 add a search box, related links and popular related
pages, especially if you can tweak it based on url
2. Adding some internal links - mainly for SEO as you don't
want to modify viewed content and making it flash
3. Adding in a Video into a page (replace an image with
YouTube)
4. Out of stock in your size click here
5. Out of stock - similar items search

102. Inserting JSON LD into a page
1. Organisation / site search
2. Ecom (reviews & product)
3. BreadCrumbs
4. OrderAction
Editing the page
1. 404 add a search box, related links and popular related
pages, especially if you can tweak it based on url
2. Adding some internal links - mainly for SEO as you don't
want to modify viewed content and making it flash
3. Adding in a Video into a page (replace an image with
YouTube)
4. Out of stock in your size click here
5. Out of stock - similar items search
Social
1. Adding Social Scripts to the page for share buttons
2. Enhancing with Quote, feature on Facebook
3. Embedding a feed (Juicer.io for example)

103. Inserting JSON LD into a page
1. Organisation / site search
2. Ecom (reviews & product)
3. BreadCrumbs
4. OrderAction
Editing the page
1. 404 add a search box, related links and popular related
pages, especially if you can tweak it based on url
2. Adding some internal links - mainly for SEO as you don't
want to modify viewed content and making it flash
3. Adding in a Video into a page (replace an image with
YouTube)
4. Out of stock in your size click here
5. Out of stock - similar items search
Social
1. Adding Social Scripts to the page for share buttons
2. Enhancing with Quote, feature on Facebook
3. Embedding a feed (Juicer.io for example)
Metadata
1. Title Tags, improve or tweak based on scraped content
2. Canonical Tags
3. Description tags
4. Social tags don’t apear to work (test again?)
5. Mobile deeplinks (for Google Indexation)
6. Pre – load, fetch & render

104. Inserting JSON LD into a page
1. Organisation / site search
2. Ecom (reviews & product)
3. BreadCrumbs
4. OrderAction
Editing the page
1. 404 add a search box, related links and popular related
pages, especially if you can tweak it based on url
2. Adding some internal links - mainly for SEO as you don't
want to modify viewed content and making it flash
3. Adding in a Video into a page (replace an image with
YouTube)
4. Out of stock in your size click here
5. Out of stock - similar items search
Social
1. Adding Social Scripts to the page for share buttons
2. Enhancing with Quote, feature on Facebook
3. Embedding a feed (Juicer.io for example)
Metadata
1. Title Tags, improve or tweak based on scraped content
2. Canonical Tags
3. Description tags
4. Social tags don’t apear to work (test again?)
5. Mobile deeplinks (for Google Indexation)
6. Pre – load, fetch & render
1.Konami Code
1. It creates links and is just fun
2. Raptorize!

105. Inserting JSON LD into a page
1. Organisation / site search
2. Ecom (reviews & product)
3. BreadCrumbs
4. OrderAction
Editing the page
1. 404 add a search box, related links and popular related
pages, especially if you can tweak it based on url
2. Adding some internal links - mainly for SEO as you don't
want to modify viewed content and making it flash
3. Adding in a Video into a page (replace an image with
YouTube)
4. Out of stock in your size click here
5. Out of stock - similar items search
Social
1. Adding Social Scripts to the page for share buttons
2. Enhancing with Quote, feature on Facebook
3. Embedding a feed (Juicer.io for example)
Metadata
1. Title Tags, improve or tweak based on scraped content
2. Canonical Tags
3. Description tags
4. Social tags don’t apear to work (test again?)
5. Mobile deeplinks (for Google Indexation)
6. Pre – load, fetch & render
1.Konami Code
1. It creates links and is just fun
2. Raptorize!
2.Signup Scripts & Growth hacking
1. Give me your email
2. REALLY YOU WANT TO SUBSCRIBE
3. Tweet to download

106. Inserting JSON LD into a page
1. Organisation / site search
2. Ecom (reviews & product)
3. BreadCrumbs
4. OrderAction
Editing the page
1. 404 add a search box, related links and popular related
pages, especially if you can tweak it based on url
2. Adding some internal links - mainly for SEO as you don't
want to modify viewed content and making it flash
3. Adding in a Video into a page (replace an image with
YouTube)
4. Out of stock in your size click here
5. Out of stock - similar items search
Social
1. Adding Social Scripts to the page for share buttons
2. Enhancing with Quote, feature on Facebook
3. Embedding a feed (Juicer.io for example)
Metadata
1. Title Tags, improve or tweak based on scraped content
2. Canonical Tags
3. Description tags
4. Social tags don’t apear to work (test again?)
5. Mobile deeplinks (for Google Indexation)
6. Pre – load, fetch & render
1.Konami Code
1. It creates links and is just fun
2. Raptorize!
2.Signup Scripts & Growth hacking
1. Give me your email
2. REALLY YOU WANT TO SUBSCRIBE
3. Tweet to download
3.Evil
1. Capturing email addresses to retarget to …
2. Point the canonical tags to point to a
parameterised version, this then has links to a
version which embeds the links you want…. This
version, check the UA and target only Google,
when it is Google insert links to a site you want to
rank for …. (are you following?)
3. Konami code to Rick Roll
4. Update dates of WP posts to make them seem
more relevant

107. Inserting JSON LD into a page
1. Organisation / site search
2. Ecom (reviews & product)
3. BreadCrumbs
4. OrderAction
Editing the page
1. 404 add a search box, related links and popular related
pages, especially if you can tweak it based on url
2. Adding some internal links - mainly for SEO as you don't
want to modify viewed content and making it flash
3. Adding in a Video into a page (replace an image with
YouTube)
4. Out of stock in your size click here
5. Out of stock - similar items search
Social
1. Adding Social Scripts to the page for share buttons
2. Enhancing with Quote, feature on Facebook
3. Embedding a feed (Juicer.io for example)
Metadata
1. Title Tags, improve or tweak based on scraped content
2. Canonical Tags
3. Description tags
4. Social tags don’t apear to work (test again?)
5. Mobile deeplinks (for Google Indexation)
6. Pre – load, fetch & render
1.Konami Code
1. It creates links and is just fun
2. Raptorize!
2.Signup Scripts & Growth hacking
1. Give me your email
2. REALLY YOU WANT TO SUBSCRIBE
3. Tweet to download
3.Evil
1. Capturing email addresses to retarget to …
2. Point the canonical tags to point to a
parameterised version, this then has links to a
version which embeds the links you want…. This
version, check the UA and target only Google,
when it is Google insert links to a site you want to
rank for …. (are you following?)
3. Konami code to Rick Roll
4. Update dates of WP posts to make them seem
more relevant
4.Personalisation
1. Capture cookies on behaviour, use to enhance
2. Use campaign source to inject a custom message
(first

108. Inserting JSON LD into a page
1. Organisation / site search
2. Ecom (reviews & product)
3. BreadCrumbs
4. OrderAction
Editing the page
1. 404 add a search box, related links and popular related
pages, especially if you can tweak it based on url
2. Adding some internal links - mainly for SEO as you don't
want to modify viewed content and making it flash
3. Adding in a Video into a page (replace an image with
YouTube)
4. Out of stock in your size click here
5. Out of stock - similar items search
Social
1. Adding Social Scripts to the page for share buttons
2. Enhancing with Quote, feature on Facebook
3. Embedding a feed (Juicer.io for example)
Metadata
1. Title Tags, improve or tweak based on scraped content
2. Canonical Tags
3. Description tags
4. Social tags don’t apear to work (test again?)
5. Mobile deeplinks (for Google Indexation)
6. Pre – load, fetch & render
Konami Code
1. It creates links and is just fun
2. Raptorize!
Signup Scripts & Growth hacking
1. Give me your email
2. REALLY YOU WANT TO SUBSCRIBE
3. Tweet to download
Evil
1. Capturing email addresses to retarget to …
2. Point the canonical tags to point to a
parameterised version, this then has links to a
version which embeds the links you want…. This
version, check the UA and target only Google,
when it is Google insert links to a site you want to
rank for …. (are you following?)
3. Konami code to Rick Roll
4. Update dates of WP posts to make them seem
more relevant
Personalisation
1. Capture cookies on behaviour, use to enhance
2. Use campaign source to inject a custom message
(first

109. Why I am a
little paranoid
about GTM
Imagine your boss fired you, for being an
untrustworthy fellow …Imagine
Imagine you are an untrustworthy fellowImagine
Imagine they still left you GTM accessImagine
Imagine you could change the canonical URLsImagine
Imagine you could sneak relevant links into pages
that only Google could see …Imagine

111. Sometimes,
post its aren’t
the right answer
and sometimes
GTM isn’t an all
in one CMS
testing SEO
solution

112. Thanks!
• Check out awesome posts on
• Moz.com for GTM & SEO blog posts
(sadly not by me)
• Simoahava.com for GTM tips
• TakeItOffline.co.uk
for articles & a bi-monthly roundtable by me & others…
• Twitter @dergal
• Connect on linkedin.com/in/dergal