14 March 2013 · PPK
When Chris Zacharias, then web developer at YouTube, brought back the page weight of a video page from 1.2Mb to 94Kb, he was stunned to see that the average page latency actually increased instead of the expected decrease.
The reason? Many phone users who didn't have a prayer of loading the old page, could just about get the new one on their crappy mobile connections, albeit with very high latencies. So the change gave YouTube countless new users, but they brought new problems. Still, the new situation is a distinct improvement over the old one, despite increased average latency.