rareness

This is already shown by the rareness of a google 404.

It's been a myth for decades that the price of a diamond was somehow correlated with its rareness.

Never heard of. Whereas despite its rareness there nevertheless are lottery winners.

There are lots of dimensions we consider for AD; at the end of the day most of them boil down to some reflection of either “badness" or "rareness".

The TSA spends billions and hassles everyone despite the relative rareness of air-travel attacks.

So, I'm not sure how many people who were willing to send off their cd's themselves would do the due diligence to find out the rareness of their own collection.

The rest of the list is innovation as defined by minor evolution or profitability or extreme rareness such that is irrelevant.

However the rareness of uncovering organized conspiracies suggests they are rarely attempted more than it suggests some hypercompetent class of conspirators.

Leakage, customs, national security issues, etc. If the government of a country says they need to inspect a specific cargo container or you can't come into port, it's easier to make that possible at sea rather than having to steam elsewhere and completely unload, especially since you'd likely have to refuel en route and it would be a very long trip due to the rareness of ports capable of handling such ships.