Scarcity is a requirement for a good to be economic. However, http://www.onethousandpaintings.com/ offer something that could be offered by thousands of artists out there. So, it is not scarce. Or is it?
Painting a Miro or a Picasso is only within the painters’ own ability, and I don’t want to buy some cheap street plagiarism. But some people actually do, and these copied paintings sell on the streets. They don’t probably sell to me and you, but they sell to a few to which the good is scarce. To those few, the painting either has an economic value, or its utility is fully artistic and they assign zero value to money. Assuming they are not infinitely rich, because they could buy the original Miro or Picasso, it only leaves us with two options: either they are infinitely stupid not to assign value to money, or the copied painting truely has some economic value.
Corolary: don’t try to market to everybody, but create scarcity for a few to which the goods have economic value.