Perhaps because we really hate the awful old carpeting on our own stair treads and keep fantasizing about tearing it out.
Designed by Liza Phillips, a New York artist with an obvious appreciation of color, the stair treads are made in Nepal from Himalayan wool. They're available in four color sets (berry, lava, mineral, and moss), each with six solid colors and six related patterns, and they can be rearranged or replaced.
("Moss" is shown to the right, "lava" above.)
You can feel good about buying these: They're not only beautiful, they're green. The Tibetan manufacturers hand spin their wool and use traditional vegetable dyes or eco-friendly Swiss Ciba colors.
Standard treads are $70, top and bottom treads are $90. They're sold directly, here.