Saying that he could easily require double the customers to bring in the same revenue is not really an assumption, it's a very probable statement. I think saying that he needs double the customers is a very generous estimate, he could in fact need well more than that, depending on the average purchase of his consumer. It is very doubtful that the average purchase after viewing the images would be greater than the $30 mark though, in my opinion. That's of course just what it is, an opinion. As with your example, people could and would choose from his several options, but his median customer would still need to spend $30 or more for him not to require a doubling of his customer base. You are definitely correct though, the only way he will find out is through some experimentation. Perhaps someday we'll find out how it worked :