survival analysis for marketing attribution · regression in many cases, log data is available only...

Revolution Confidential

Survival Analysis for

Marketing Attribution

LondonR

July 2013

Andrie de Vries

Business Services Director – Europe

@RevoAndrie

Revolution Analytics

@RevolutionR

Revolution ConfidentialWho am I?

CRAN package ggdendro

StackOverflow

LondonR, July 2013 2

Revolution ConfidentialFrom Toledo to Albacete


Revolution ConfidentialRent a car?


Revolution Confidential… or take a bus?


Revolution Confidential… but what’s happening here?


Revolution ConfidentialMarketing attribution: the Question

How to attribute conversion success to marketing spend?

Where to spend the next marketing dollar?


Revolution ConfidentialAgenda

Digital marketing attribution

Using Survival models

At scale, on big data


Revolution ConfidentialTwo-click conversion journey

Click1:

Open landing page

Click 2:

Sign up to offer


Revolution ConfidentialTypical conversion journey…

Impressions

• Banner ad

• Page post ad

• Sponsored tweet

• Search ad

Click

• Landing page

• Special offer

• Application form

Conversion

• Sign up

• Ask for more detail

11LondonR, July 2013

Revolution Confidential…but no two journeys are the same…

Impressions

• Banner ad

• Page post ad

• Sponsored tweet

• Search ad

Click

• Landing page

• Special offer

• Application form

Conversion

• Sign up

• Ask for more detail


Person 2

Person 3

Person 1


Attribution models

Last click only

All events even

Rule based

Statistical modelling

…so how to attribute the value?


Person 2

Person 3

Person 1

Revolution ConfidentialAttribution with statistical modelling

Regression

In many cases, log data is available only

for conversions

And when non-conversion data is available,

these people may convert in near future


Revolution ConfidentialAttribution with statistical modelling

Regression

In many cases, log data is available only

for conversions

And when non-conversion data is available,

these people may convert in near future

Survival analysis

Use time to conversion as dependent

variable

Can use each interaction (view or click)

as an observation

Can include censored (incomplete) data

No need to flatten the data


Revolution ConfidentialSurvival models

Kaplan-Meier survivor function

Cox proportional hazards model

𝑆𝑘𝑚 =

𝑡𝑖<𝑡

𝑟 𝑡𝑖 − 𝑑(𝑡𝑖)

𝑟(𝑡𝑖)

𝐿(𝛽) = 𝐿𝑖(𝛽)

𝐿𝑖(𝛽) =𝑟𝑖 𝑡∗

𝑗 𝑌𝑗 𝑡∗ 𝑟𝑗 𝑡∗

𝜆 𝑡; 𝑍𝑖 = 𝜆0(𝑡)𝑟𝑖(𝑡) Hazard function

𝑟𝑖 𝑡 = 𝑒𝛽𝑍𝑖(𝑡) Risk score

Likelihood that

individual i dies

Partial likelihood

> library(survival)

> Surv(…)

> library(survival)

> coxph( Surv(…) ~ …)


Revolution ConfidentialWhat is death?

LondonR, July 2013

Medicine: actual death of patient

Engineering: failure of component

18

Revolution ConfidentialWhat is death?

LondonR, July 2013

For attribution: cookie conversion

19


Worked example

Attribution of digital media for

telecoms client


Revolution ConfidentialRead the data

> rdsFile <- "survival_data.rds"

> xd <- readRDS(rdsFile)

> class(xd)

[1] "data.table" "data.frame"

> nrow(xd)

[1] 775782

> ncol(xd)

[1] 31


Revolution ConfidentialWhat does the data look like?> xd[1:25, 1:6, with=FALSE]

id Conversion.Time Event.Number Event.Time Event.Type Campaign

1: 10101:49721794 01/10/2012 00:05 1 01/10/2012 00:02 Click Free Sims

2: 10101:49721801 01/10/2012 00:05 1 29/09/2012 16:25 View BAU High Media






















Revolution ConfidentialHistogram of cookie lifetime

LondonR, July 2013

Impressions and clicks in customer journey

Cookie duration (days)

Eve

nts

(im

pre

ssio

ns a

nd

clicks)

0 5 10 15 20 25 30

05

00

00

15

00

00

25

00

00

23

Revolution ConfidentialFitting the model

LondonR, July 2013

> library(survival)

> fitp <- coxph(

Surv(times, event=Converted) ~ Type +

Event.Type +

Supplier +

PrevClicks +

AdFormat,

data=xd)

24

Revolution ConfidentialWhat does the data say?AdFormat Event.Type PrevClicks Supplier Type

0

1

2

Super

Sky-1

60x600

Leaderb

oard

- 728x90

MP

U-3

00x250

Vie

w

Click

Pre

vC

licks

MexA

d

Specific

Media

Valu

eC

lick

Ebay

AO

L N

etw

ork

Gum

tree

Google

Dis

pla

y N

etw

ork

Facebook A

PI

Pay m

onth

ly S

IM

Contr

act

Phone

SIM

only

Exp

on

en

tia

ted

co

eff

icie

nt



AdFormat Event.Type PrevClicks Supplier Type

0

1

2

Super

Sky-1

60x600

Leaderb

oard

- 728x90

MP

U-3

00x250

Vie

w

Click

Pre

vC

licks

MexA

d

Specific

Media

Valu

eC

lick

Ebay

AO

L N

etw

ork

Gum

tree

Google

Dis

pla

y N

etw

ork

Facebook A

PI

Pay m

onth

ly S

IM

Contr

act

Phone

SIM

only

Exp

on

en

tia

ted

co

eff

icie

nt

What does the data say?

• Advertise the right product!

• Some suppliers are better at generating

conversion

• But note the data wasn’t an unbiased

experiment!


Revolution ConfidentialEstimated hazard function

LondonR, July 2013

> x <- survfit(fitp)

> xx <- with(x, data.frame(time, surv, upper, lower))

> ggplot(xx, aes(time, surv)) + geom_step() …

27

Revolution ConfidentialCase study: Datasong

Profile:

Multi-channel marketing analytics

Software developer and service provider

Growing, innovative, cost-conscious

Technology:


Revolution ConfidentialModeling the Baseline Hazard

LondonR, July 2013

Capture nonlinear trends in

baseline, while overlaying

marketing treatment variables

as well as other customer

attributes

Revolution R package used:

• RevoScaleR

Revolution R functions used:

• rxImport()

• rxSummary()

• rxCube()

• rxLogit()

• rxPredict()

• rxRoc()

30

Revolution ConfidentialTransformations

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Catalog Email

31

Revolution ConfidentialOutcome

Massively scalable infrastructure

Attribution and optimization at individual customer level for clients

such as Williams-Sonoma

Client saved $250K in one campaign

Rapid deployment of customer-specific models

Innovative techniques, e.g. GAM Survival models

Performance improvement

Experienced 4x performance improvement on 50 million records



33

www.revolutionanalytics.com Twitter: @RevolutionR

The leading commercial provider of software and support for the popular open source R statistics language.

LondonR, July 2013

survival analysis for marketing attribution · regression in many cases, log data is available only...

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