Copeland's TN tokens book lists the Knoxville one as "rare". It is a "store card" of the relatively modern era.
The one for Spiegels was indeed for use with their catalog. It was a giveaway to entice people to open a credit account with them. I suspect they mailed them to potential customers from mailing lists they had acquired. I can remember my parents getting one of these in the 1950s.
John