You have reversed my argument. They were not encyclopedic because they were bestsellers; rather thay became bestsellers because they were encyclopedic. With events like the recent hurrican Katrina it is not unusual for people to ask, "What was the biggest previous hurrican?" or "Were there any other famous hurricanes that began with the letter 'K'?" You underestimate the thirst that people may have for information that may otherwise be trivial or useless. If they can come to us to discover these things that they could not find anywhere they will come back. We need only insure that even our trivial information is verifiable.
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See [[Hurricane]] and [[Category:Hurricanes]] should be the answer to those example questions. We don't need an article [[Biggest hurricane]] or [[List of hurricanes starting with the letter K]].