Cups and Balls...are...simply, Cups and Balls.
Surprisingly, to some/most, is the time required to make your routine perfect.
However, once you've learned the 'basic' routine and invested the practice time to become proficient, everything else is easy.
Your 'balls' can be almost anything e.g. tissue, fruit, yarn, etc.
That brings us here...these "Technicolor Cups and Balls" are just a new utility to enhance your act. Painted cups with crocheted balls...ta da!
As the ad copy states "...We describe a basic routine to get you started. More elaborate and interesting routines (which are beyond the scope of instruction) are available in the magic market..."
So, in conclusion, any other sources of info in re: Cups and Balls that you may already be familiar with would be helpful ;-)