Google’s Shrinking Ad-Tech Business

Quick quiz: Which part of Google’s business has declined for eight straight quarters? If you guessed the Google network business—which sells advertising on other companies’ websites—you deserve an A in Google-nomics.

In the second quarter, reported on Tuesday, Google reported that revenue from the network operation shrank 5% even as ad sales on its own properties (search and YouTube, primarily) rose 13.7%. This continues a steady trend: Over the past 18 months, network revenue has shrunk 4%, while revenue on Google’s own properties has grown 10%.