Big surprise inside a used CD

Found a copy of Victor Wooten’s Palmystery on CD at my local used book store for $3. Opened it up to find the CD in immaculate shape and the booklet appears to be signed by Victor himself! Stoked! Anyone know if he did this for the first run of the CDs or if it’s common to find?
E7F8A816-FFA7-4920-B722-87A127CF64C1.jpeg
00F97774-3AA2-4078-AC04-0B3623ECC98B.jpeg