http://www.minilps.net/mini-lp-replicas/what-is-an-obi-strip/What is an obi strip?
Obi has a couple of meanings.
On this site it IS NOT an article of Japanese clothing (a sash or belt for securing and decorating a kimono).
On this site it is the small piece of paper included with a CD or LP usually wrapped around the left hand spine of the item. (See also promo obi.)
An obi strip is, for all intents and purposes, a disposable item. It provides information to the seller and to the buyer (mostly in Japanese) about the item being sold. Once the item has been sold to the consumer it is basically useless (it has served its purpose).
Although not strictly ephemera (disposable paper items such as postage stamps and cigarette and bubble gum cards), obis are collectable items in their own right.
To non-Japanese reading buyers, the dates on the obi provide an indication of when the item was made or became available.