Sometime along the time of
British metric conversion,
The Powers That Be ran up to a quandry - what to do with the
arseload, known worldwide as the
British Assload. No suitable
metric counterpart was immediately available. Thus, an equivalent mass, the
metric assload was invented.
Not to be outdone, the Canadians soon got in on the act during their very own metric conversion. Sensing that a metric assload wasn't large enough for measuring things such as beer, ice, snowfall or hooses per square kilometer, the metric shitton was set to be equal to 100 of the British's new metric assload.
After working with hundreds and thousands of these newfangled metric assloads, lazy American scientists proposed yet another unit as "it would afford us to use less 'a them there zeros". Oddly enough, it was found that 2000 assloads troy was both ten times as large as the metric shitton and one thousand times larger than the metric assload, the metric fuckton was put into service via a gentleman's agreement.
While the metric fuckton is often left out of english-metric conversion tables, physics books and my 26th edition of the Machinery's Handbook, the unit is often used in day to day life of the scientific elite to measure such things as paperwork to be done or the amount of shit given by coworkers.
noded at the request of The Custodian, inspired by a conversation in the catbox, props to Caliban