American Airlines was one of the first airlines to charge for a pillow and blanket. One year later, the charge remains and can be considered permanent.
On an American flight from Dallas-Fort Worth to Honolulu I decided to purchase a blanket pack to see what you get for eight dollars. The pack includes a fleece blanket made of 100% polyester and an inflatable neck pillow in a clear zipper case. The case could be used for toiletries as noted on the pack's tag which calls the combo a comfort kit. With careful folding of each item, it's possible to repack the two items back into the case. A coupon for $10 off a $30 purchase at Bed Bath & Beyond is included.
The blanket is surprisingly soft and unfolds to the the standard size of blankets that were once free in the coach cabin. As for the pillow I much prefer to have a regular pillow for my back rather than the one for my neck. So now I have both for future flights but they are also two more things to pack.
JetBlue and US airways also charge for a blanket-and-pillow set. They both charge $7 but US Airways includes eye shades and earplugs.