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Practical Multi-Task Learning for Rare Conversions in Ad Tech

Information Retrieval 2025-07-29 v1 Machine Learning

Abstract

We present a Multi-Task Learning (MTL) approach for improving predictions for rare (e.g., <1%) conversion events in online advertising. The conversions are classified into "rare" or "frequent" types based on historical statistics. The model learns shared representations across all signals while specializing through separate task towers for each type. The approach was tested and fully deployed to production, demonstrating consistent improvements in both offline (0.69% AUC lift) and online KPI performance metric (2% Cost per Action reduction).

Keywords

Cite

@article{arxiv.2507.20161,
  title  = {Practical Multi-Task Learning for Rare Conversions in Ad Tech},
  author = {Yuval Dishi and Ophir Friedler and Yonatan Karni and Natalia Silberstein and Yulia Stolin},
  journal= {arXiv preprint arXiv:2507.20161},
  year   = {2025}
}

Comments

Accepted to RecSys 2025

R2 v1 2026-07-01T04:20:43.432Z