The Britannica, the oldest continuously published encyclopedia in the English language, has become a luxury item with a $1,395 price tag. It is frequently bought by embassies, libraries and research institutions, and by well-educated, upscale consumers who felt an attachment to the set of bound volumes. Only 8,000 sets of the 2010 edition have been sold, and the remaining 4,000 have been stored in a warehouse until they are bought.
According to the article, it took only 11 years for Wikipedia to take over:
Since it was started 11 years ago, Wikipedia has moved a long way toward replacing the authority of experts with the wisdom of the crowds. The site is now written and edited by tens of thousands of contributors around the world, and it has been gradually accepted as a largely accurate and comprehensive source, even by many scholars and academics.
I kind of want to buy the last copy. That would be cool. I have no idea where I would put it though. My iPad or Kindle maybe?