WTF is this?

I had something really funny happen to me this weekend when I tried selling a custom mountain bike. So this guy comes to my house and says he's interested in the bicycle. Clearly I was excited because I had listed it on Craigslist for .75 BTC. He then says that he likes the bike and wants to buy it. I said awesome, well it's just .75 BTC which is a great deal considering all the aftermarket parts.

However, he claimed that he didn't know what BTC or Bitcoin meant and couldn't offer that. He then pulls out these sheets of paper with numbers and faces printed on them. I said WTF is that??? He called them "dollars" and said he would offer 400 "dollars" for the bicycle. After a good 15 second laugh I realized that he was actually serious and then I asked if I could take a picture of one of them (see above).

Once the giggling subsided I proceeded to ask him about these sheets of paper. He couldn't give me any explanation as to why they have value. So then I said well why would I accept them for my mountain bike??? He said well he accepted them at his job as a form of payment. He then claimed that if I accepted these that other people would accept them as a form of payment.

I was skeptical, so we couldn't make a deal. Subsequently I let him know that if he traded those for BTC and gave them to me then the bike would be all his. Can anyone tell me what the hell these things are? Am I missing something?

/r/Bitcoin Thread Link - i.imgur.com