2,693 research outputs found
Cost-sensitive Learning for Utility Optimization in Online Advertising Auctions
One of the most challenging problems in computational advertising is the
prediction of click-through and conversion rates for bidding in online
advertising auctions. An unaddressed problem in previous approaches is the
existence of highly non-uniform misprediction costs. While for model evaluation
these costs have been taken into account through recently proposed
business-aware offline metrics -- such as the Utility metric which measures the
impact on advertiser profit -- this is not the case when training the models
themselves. In this paper, to bridge the gap, we formally analyze the
relationship between optimizing the Utility metric and the log loss, which is
considered as one of the state-of-the-art approaches in conversion modeling.
Our analysis motivates the idea of weighting the log loss with the business
value of the predicted outcome. We present and analyze a new cost weighting
scheme and show that significant gains in offline and online performance can be
achieved.Comment: First version of the paper was presented at NIPS 2015 Workshop on
E-Commerce: https://sites.google.com/site/nips15ecommerce/papers Third
version of the paper will be presented at AdKDD 2017 Workshop:
adkdd17.wixsite.com/adkddtargetad201
XRay: Enhancing the Web's Transparency with Differential Correlation
Today's Web services - such as Google, Amazon, and Facebook - leverage user
data for varied purposes, including personalizing recommendations, targeting
advertisements, and adjusting prices. At present, users have little insight
into how their data is being used. Hence, they cannot make informed choices
about the services they choose. To increase transparency, we developed XRay,
the first fine-grained, robust, and scalable personal data tracking system for
the Web. XRay predicts which data in an arbitrary Web account (such as emails,
searches, or viewed products) is being used to target which outputs (such as
ads, recommended products, or prices). XRay's core functions are service
agnostic and easy to instantiate for new services, and they can track data
within and across services. To make predictions independent of the audited
service, XRay relies on the following insight: by comparing outputs from
different accounts with similar, but not identical, subsets of data, one can
pinpoint targeting through correlation. We show both theoretically, and through
experiments on Gmail, Amazon, and YouTube, that XRay achieves high precision
and recall by correlating data from a surprisingly small number of extra
accounts.Comment: Extended version of a paper presented at the 23rd USENIX Security
Symposium (USENIX Security 14
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