I love the simplicity of having one airline but I may need to take on the extra hassle if it means more upgrades.

What are the downsides for DL creating a DD tier? Certainly there is a real expense to them - they must print new cards, change websites, create new marketing materials,new training for employees etc - it would cost them tens of millions for sure - but don't you think they would attract high volume flyers from other airlines who would now fly DL more often? Wouldn't these new flyers offset that cost and perhaps even create more profits? Because DL has such a large network of routes - many high volume flyers might be attracted to such a high medallion level. Frequent flyers on non-DL airlines could move to DL and still take mostly direct flights. I would think such a tier would be good for DL's bottom line????