Airlines are able to sell an e+ product quite successfully. So we know there is some interest in more room. This is another type of e+ product - but width instead of foot room. Except that it is not fully a room issue - the seat cushion is still economy size, we would probably be talking European business class where there is a small table in between the seats. But you do get more shoulder room. You would still be getting economy level service.

From an airline view, selling the two adjacent seats at %150 would in theory make up for the cost of the "lost" middle seat. Obviously there are a few other factors to consider, but I am trying to determine if there is enough market, and how much market, there would be if an airline were to offer say 5 rows of Economy Wide.