I was never really sure what the "paranoid" term meant in old poker chip ads. I kind of assumed it meant that if you were paranoid, they would guarantee not to sell anyone else chips with your design on them. But as your scan shows, the term was also applied to generic chips.

Finally googled up a definition, which is:

2.The trade-name for a plastic material which resembles celluloid, used for dominoes, poker chips, etc.

So I guess the "...oid" comes from celluloid. Does that mean that many of what we call "antique clay chip" are really plastic???