What are those E-Bay auctions selling that list a useless item and state anything else received is a gift?

I’m just curious. Sometimes when I’m killing time, I look at those “really weird stuff” auctions on ebay. What are they selling when they list something such as two matches and then say “I am selling two matches, anything else you receive is a gift” I’m not going to waste my money on these but am curious why people are paying $200 for whatever it is they are selling.