Abstract: Search-Log Anonymization and Advertisement: Are They Mutually Exclusive?

The revenue of search-engine providers strongly depends on targeted advertisement. Targeted advertisement is becoming more reliant on personal data. This puts user privacy at risk. One way to improve privacy is to anonymize search logs, but this reduces usefulness for ad placement. Further, the usefulness depends on the target function used for the anonymization. This paper is the first to study this tradeoff systematically. We quantify the usefulness of an anonymized search log for advertisement purposes, by estimating outcomes such as the number of clicks on ads or the number of ad impressions possible after anonymization. A main result is that anonymized search logs are still useful for advertisement purposes, but the extent strongly depends on the target function.