I love marked cards. I love purple cards. And I love things that are clever.
Alas, it's
hard to recommend these (I bought a bunch of decks in my excitement, alas).
The video is
earnestly produced, even if they didn't realize that cameras have a zoom feature which would have
helped a lot.
The method is arcane and fussy, and the fact that it's not shown in action in
performance is a clue that it's not really for typical engagements.
There are better
options.
But points for being incredibly clever. Binary!