1. The power of
probabilistic thinking in
SEO
@bertiecharlton
Andrew Charlton
Managing Director of Crawl

2. SEOs are no better than
a coin toss at predicting
SEO performance.
@bertiecharlton

3. SEOs are also no better at predicting which of
two pages should rank for a keyword.
@bertiecharlton
PAGE 1?
PAGE 2?
https://moz.com/blog/can-you-guess-which-page-ranks-better

4. SEOs are also no better at predicting which of
two pages should rank for a keyword.
@bertiecharlton
PAGE 1?
https://moz.com/blog/can-you-guess-which-page-ranks-better
PAGE 2?
46%

5. @bertiecharlton

6. @bertiecharlton
You instinctively think
in probabilities.

7. @bertiecharlton
We’re not so good
at communicating
uncertainty.

8. SEOs who think
probabilistically, can:
@bertiecharlton
Estimate their impact on performance
Make more of the right decisions
Create strategies that balance risk/reward
Communicate uncertainty

9. @bertiecharlton
Let’s talk about
Enrico Fermi.

10. @bertiecharlton
What information
would allow me to best
answer the question?

11. How many piano tuners are there in Chicago?
@bertiecharlton
# of Pianos in
Chicago.
How often
pianos are
tuned.
How long it
takes to tune
a piano.
# of hours per
year a piano
tuner works.

12. How many piano tuners are there in Chicago?
@bertiecharlton
# of people in
Chicago?
% of people that
own a piano?
1.5m 3m
2.5m
2 in 100? (guesstimate)
# of Pianos in
Chicago.
50,000

13. Example: our client provides meeting
room spaces across the UK.
@bertiecharlton
“How much organic
traffic could we attract
by focusing on
coworking spaces in
all of our locations?”
Est. organic traffic per
local landing page.
# of local landing
pages.

14. @bertiecharlton
“How much organic
traffic could we attract
by focusing on
coworking spaces in
all of our locations?”
Est. organic traffic per
local landing page
# of local landing
pages
Est. CTR
Avg. search volume
Est. competitor traffic
Example: our client provides meeting
room spaces across the UK.

17. 1. Which keywords are most
similar?

18. Aggregate CTR by average position.
@bertiecharlton
2. Aggregate CTR by
position. 0.85%

19. 60,000 0.85% 510
264 750
x =
Search volume CTR Clicks p/m
@bertiecharlton

20. @bertiecharlton
How do you make more
of the right decisions?

21. Reward
Probability
of outcome
x =
What could you
achieve?
@bertiecharlton
Expected
value
What are the chances
this will happen?

22. “Should we focus on the coworking space
or expand internationally in the US?”
@bertiecharlton
50%
50%
790
507
70%
30%
Coworking
space
US expansion
Upper estimate (750)
Lower estimate (264)
Upper estimate (1,000)
Lower estimate (300)

23. Can you test
this?
Have others done
this before?
Have you done
this before?
How do you improve your subjective
probabilities?
@bertiecharlton
Split-testing?
Partial rollout?
Same change
(this/others)?
Similar change
(this/others)?
Competitors?
Other sites?
Studies?
Confidence

24. Use common
sense.
@bertiecharlton

25. SEO strategies
should be like an
investment portfolio.
@bertiecharlton
Digital PR
campaign
Website migration
Technical SEO fixes

26. Smaller bets can prove impact early and bridge
the trust gap between stakeholder or client.
@bertiecharlton
Added
canonical tags
Minor title
tag changes
XML sitemap
index
Category
Restructure
20,000
25,000
30,000
35,000
40,000
45,000
50,000
55,000

27. @bertiecharlton
There’s power in
tiny gains.

28. Your words set
expectations.
@bertiecharlton
20%- 80% probability
80% probability

29. @bertiecharlton
“We will achieve a 40%
increase in organic traffic in 12
months.”

30. @bertiecharlton
“There’s a 95% probability
organic traffic will increase by
20-40% in the next 12 months.”

31. @bertiecharlton
“There’s a 95% probability
organic traffic will increase by
20-40% in the next 12 months.”
“We don’t have enough data to
provide an estimate. ”

32. Anchor your estimates with
business and market realities.
@bertiecharlton
Compare your estimates with market growth.
Control your unknowns.
Clarify your dependencies.

33. Thank you.
@bertiecharlton
@bertiecharlton
crawlconsultancy.com
keywordsinsheets.com