In brief, it attempts to track user satisfaction with search results by measuring how long do people stay on pages. It does that by appending fromsearch=1 to links for 0.5% of users. However, this results in page views being uncached and thus increasing HTML load time by a factor of 4-5 and, consequentially, kicking even short pages' first paint outside of comfort zone of 1 second - and that's measured from the office, with ping of 2-3 ms to ulsfo. My concern here is that as a result we're trying to measure the very metric we're screwing with, resulting in experiment being inaccurate.

Can we come up with a way of measurement that's less intrusive or alter the requirements of the experiment?
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