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TRANSCRIPT
I Always Feel Like
Somebody’s Watching Me Measuring Online Behavioural
Advertising
Juan Miguel Carrascosa (Univ. Carlos III de Madrid)
Jakub Mikians (Universitat Polytechnic Catalunya)
Rubén Cuevas (Univ. Carlos III de Madrid)
Vijay Erramilli (Guavus)
Nikolaos Laoutaris (Telefonica Research)
WHAT? • A methodology for detecting behavioural
advertising for specific topics, for example: o Cars, sports or computers
o Sensitive topics: health, politics or sexual orientation
• Eventually it will become a tool for auditing specific
websites and trackers
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WHY? • Online Behavioural Advertising (OBA)
…is rising and is here to stay
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… but PRIVACY concerns are rising too
• Tracking, Cookies, Fingerprinting…
• Behavioural targeted Advertising is the
process of: o Collecting information (from users)
o Show ads (based on the information)
Because of tracking
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Main idea of our methodology
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CLEAN PROFILE/BROWSER
WEBPAGES
NEUTRAL WEBPAGE
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Challenges
• Complexity of the ecosystem o Several aggregators, Ad Exchanges, Ad Networks, etc.
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Challenges
• Complexity of the ecosystem o Several aggregators, Ad Exchanges, Ad Networks, etc.
• Different types of advertising
• How to obtain datasets and automate the process
Summary of Finding
• More expensive categories are more targeted
• Sensitive categories (e.g. health, sexual
orientation… ) seem to be targeted
• Do-Not-Track flag seems to have no effect on
whether you are targeted
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METHODOLOGY
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Methodology
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SELECTION
COLLECTING ADS
TAGGING SYSTEM
FILTER PHASE
MEASURING OBA
Methodology
• Personas
• Training Pages
• Control Pages
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SELECTION
COLLECTING ADS
TAGGING SYSTEM
FILTER PHASE
MEASURING OBA
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1. Reduce profile contamination Personas with a very specific
behavioural trait
Methodology Selection of Personas and Training Pages
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1. Reduce profile contamination Personas with a very specific
behavioural trait
2. Wide range of Personas
3. Automated and systematic
manner
Methodology Selection of Personas and Training Pages
• Google Ad Words' hierarchical category system o More than 2000 categories (i.e., behavioural traits)
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Methodology Selection of Personas and Training Pages
+2000 • All Google Ad Words’ categories
240 • Google Ad Words CATEGORIZATION SYSTEM
202 • Google's ads PREFERENCES PROFILE
104 • Personas with at least 10 training pages
51 • 51 Personas with 10 training pages
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Methodology Selection of Personas and Training Pages
• Reduce profile contamination
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Methodology Selection of Control Pages
• Requirements: o Popular
o Show Ads
o Low number of identifiable tags
5 WEATHER PAGES
Methodology
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SELECTION
COLLECTING ADS
TAGGING SYSTEM
FILTER PHASE
MEASURING OBA
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Methodology Collecting Ads
Specific case: SWIMMING POOLS & SPAS
Methodology Collecting Ads
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CONTROL PAGE!!!
COLLECT ADS (landing pages)
Methodology
SOURCES o Google
o Cyren
o McAfee
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SELECTION
COLLECTING ADS
TAGGING SYSTEM
FILTER PHASE
MEASURING OBA
Methodology: Tagging Phase
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• To detect systematically relations between training
and landing pages. o Based on keywords
• 3 sources/dictionaries o INPUT: Urls /Pages
o OUTPUT: Keywords/Categories
TRAINING PAGES
LANDING PAGES (ADs)
Cyren KEYWORDS
McAfee KEYWORDS
Google KEYWORDS
Methodology
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SELECTION
COLLECTING ADS
TAGGING SYSTEM
FILTER PHASE
MEASURING OBA
• Used to identify and remove landing pages
associated with non-OBA ads:
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Methodology Filtering different types of ads
Landing Page
Retargeting
Static & Contextual
Demographic & Geographical
Training Pages
Control Pages
Clean Profile
Personas’ Similarity
Methodology
METRICS
o TTK
o BAiLP
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SELECTION
COLLECTING ADS
TAGGING SYSTEM
FILTER PHASE
MEASURING OBA
Methodology Measuring OBA: METRICS
• TTK (Targeted Training Keywords)
o MEASURES IF OBA IS HAPPENING
o MEASURES HOW MUCH A PERSONA IS
TARGETED
• BAiLP (Behavioural Advertising in Landing Page)
o MEASURES PERCENTAGE OF ADS THAT
ARE LIKELY ASSOCIATED TO OBA
o HOW MANY OF THE ADs SERVED TO A
PERSONA ARE TARGETED.
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Training Keywords
Landing Keywords
Training Keywords Ads
EXPERIMENTAL ANALYSIS
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How frequent is OBA? Are some personas more targeted than others?
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In summary, • TTK measures if OBA is happening
• BAiLP captures what percentage is due to OBA.
CORRELATION received OBA (BAiLP) and its value for the advertisers
How frequent is OBA? Are some personas more targeted than others?
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In summary, • TTK measures if OBA is happening
• BAiLP captures what percentage is due to OBA.
CORRELATION received OBA (BAiLP) and its value for the advertisers
Categories where the bid price is higher
MORE TARGETED
Is OBA applied to sensitive topics?
• Same methodology 21 sensitive personas
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Is OBA applied to sensitive topics?
• Same methodology 21 sensitive personas
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OBA in sensitive topics is LOWER than previous cases
BUT still EXIST
European Law
• To become effective on January 2016
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Geographical and Do-Not-Track
• Same methodology: o Geographical: US and ES
o Do-Not-Track: ON|OFF
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Geographical and Do-Not-Track
• Same methodology: o Geographical: US and ES
o Do-Not-Track: ON|OFF
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Geographical regions and Do-Not-Track flag
DO NOT HAVE ANY IMPACT on OBA
Conclusions
• Detecting Behavioural targeting on specific
categories is difficult but doable
• Categories that have a higher value for the
advertisers get more targeted ads
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THANK YOU
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Juan Miguel Carrascosa Univ. Carlos III de Madrid
TYPES EUROPEAN PROJECT http://www.types-project.eu/
DATA TRANSPARENCY LAB http://www.datatransparencylab.org/