Unexpected consequences, when a developer slims the size (in terms of data) of the YouTube video-watching page from 1.2M down to under 100kb.
Having just finished writing the HTML5 video player, I decided to plug it in instead of the far heavier Flash player. Bam! 98KB and only 14 requests. I threaded the code with some basic monitoring and launched an opt-in to a fraction of our traffic. After a week of data collection, the numbers came back… and they were baffling. The average aggregate page latency under Feather had actually INCREASED. I had decreased the total page weight and number of requests to a tenth of what they were previously and somehow the numbers were showing that it was taking LONGER for videos to load on Feather. This could not be possible. Digging through the numbers more and after browser testing repeatedly, nothing made sense. I was just about to give up on the project, with my world view completely shattered, when my colleague discovered the answer: geography.