re-usable book covers is promoting them not for the usual reasons of protecting your book from wear and tear, but because:
"Trashy Romance Covers
Hide your embarrassing paperbacks
with witty (or even boring) covers!"
Even more confusing most of the covers offered are emblazoned with terms generally associated with low prestige reading "trashy romance novel" (shudder), "smut", "pool book" and "summer read" for example. And the standard back is plain white with a huge logo and the name "Hide a Cover".