This is an old trick out of the direct marketing handbook, BTW. Direct marketers would send out mailers for lots of different products, asking people to respon

This is an old trick out of the direct marketing handbook, BTW. Direct marketers would send out mailers for lots of different products, asking people to respond if they were interested. They then gauged market demand by the response rate. I think this technique might actually be illegal when done over snail mail nowadays.