> So it has to fetch that 20-years old article. It doesn't have to fetch every article (statical sampling can give confidence intervals), and it doesn't have t

> So it has to fetch that 20-years old article. It doesn't have to fetch every article (statical sampling can give confidence intervals), and it doesn't have to fetch the full article: doing a "HEAD /" instead of a "GET /" will save on bandwidth, and throwing in ETag / If-Modified-Since / whatever headers can get the status of an article (200 versus 304 response) without bother with the full fetch.