Originally Posted by slowplay

It works because of our network. It doesn't work for them because of theirs and their cost structure.

There are an awful lot of sub 2 hour legs at hubs like ATL, DTW, and MSP that used to be flown by DC-9's. There are regions of the country that have too many airports too close together for the population base. Look at PIA, BMI, and SPI, all within an hour's drive of each other. DL provides service to both PIA and BMI with multiple RJ's to multiple hubs. Flying half to 2/3rds as many flights on B717 vice 50/70/76 seat RJ's gives Delta lower costs and potentially higher revenue.

For an airport that is slot constrained like LGA, up gauging is the only way to increase capacity. There are a lot of places within 3 hours of LGA. As the LGA hub is built out and connectivity increases it will be upgauged.

The C series is still a paper airplane. The 787 is over 5 years late on realizing its economic promises, and that's from a company that's built lots of different types of aircraft. At its acquisition cost, the B717 is a very competitive airframe for its intended role in Delta's network.