Piero Manzoni - Artist's Shit (Merda d'artista, 1961)

In 1961 an Italian artist named Piero Manzoni pooped in a tin can:

And then he sold it. 
He “produced” 90 of these cans, and labeled with stickers in different languages, stating:

Artist's Shit
Contents 30 gr net
Freshly preserved
Produced and tinned
in May 1961 

Where is the art in this shit? We surely know where the shit is, but is this really art? In my opinion, the fact that a lot of people from high society and intellectual critic, since  1961, declare themselves disgusted  by this work, and keep to argue how bad and degrading this is, is enough to be considered an artistic work.

Wikipedia states  “A tin was sold for €124,000 at Sotheby's on May 23 2007; in October 2008 tin 083 was offered for sale at Sotheby's with an estimate of £50-70,000. It sold for £97,250”. People is paying that much for a can of shit? Maybe shit is not art, but having the ability to sell is surely an artistic skill.