Seemed like a good idea to me! Maybe that's the reason I am not in advertising.

My thought process was.....
A 25¢ sticker on a back window of a car is seen by a great number of people (sparking some to curiosity and investigate later on the web). Of the people displaying them many of those cars will be seen in casinos where gamblers where a single chip or two may be kept, sparking a seed to a new collection.

I collected chips many years before I ever knew there was a group of people that collected them.

Disney started with a mouse, we could start with a 25¢ sticker.... not much of an investment to spark an interest.