From NYTimes.com: Mr. Whipple Left It Out: Soft Is Rough on Forests
The national obsession with soft paper has driven the growth of brands like Cottonelle Ultra, Quilted Northern Ultra and Charmin Ultra — which in 2008 alone increased its sales by 40 percent in some markets, according to Information Resources, Inc., a marketing research firm.
But fluffiness comes at a price: millions of trees harvested in North America and in Latin American countries, including some percentage of trees from rare old-growth forests in Canada. Although toilet tissue can be made at similar cost from recycled material, it is the fiber taken from standing trees that help give it that plush feel, and most large manufacturers rely on them.