[sievebrain]

Google has routinely increased profits by a huge amount through better machine learning. It's been using statistical optimisation for years. Such a massive jump almost makes me think it must be something like that, because the timing would be about right for a major rollout of a new ads optimisation engine based on their latest AI research, and 25% increase doesn't seem possible to occur naturally just through shifts in supply/demand. Only radically better ad targeting could do that.