Thanks for the suggestion.

But, quoting from the site:
Your PasswordCard has a unique grid of random letters and digits on it. The rows have different colors, and the columns different symbols. All you do is remember a combination of a symbol and a color, and then read the letters and digits from there. It couldn't be simpler!
That "unique grid" is supposedly generated by a code like ba625143531f714e that's chosen by the user. Sounds good, but what's the algo for generating the grid? If I were an attacker running the site, I would make resulting cards have only a limited number of different rows and columns. Still numerous enough to evade statistical analysis from buyers, but easy enough for an attacker to exhaust.
Van gens also introduce an attack vector: someone could upload a spoofed generator.
Perhaps a dedicated open source NXT password card generator would be a useful tool for the community.