Hey guys, new poster here, but I saw an article that seems prettty applicable to this discussion, seems like Flightglobal has been reading this thread
https://www.flightglobal.com/news/artic ... ta-458775/"ANALYSIS: What makes a focus city for Delta?"
"We've chosen these focus cities based on a strong economic environment and, really, areas where we think the Delta product will really make a difference," she said.
"Delta has three classifications for cities it considers more than a spoke. Atlanta, Detroit, Minneapolis/St Paul and Salt Lake City are its "core hubs" where it focuses on driving connectivity, says Martin."
"Boston – upgraded from a focus city just this year – Los Angeles, New York John F Kennedy and LaGuardia, and Seattle Tacoma are "coastal hubs" for Delta, she says. These are top 10 markets in the USA where the airline operates more than 150 peak day flights and offers some level of connectivity."

"We've really selected markets that have a lot of youthful presence, strong corporate standing, and where we've seen above average growth for the industry," says Martin when asked how Delta selects its focus cities.
"The cities the airline has selected generally meet these criteria. San Jose – at the centre of Silicon Valley – is a dynamic technology hub in one of the richest and rapidly growing regions in the USA, while Austin and Raleigh are both growing tech hubs in their own right. Nashville is a dynamic city in the US South with above average growth, and Cincinnati a former Delta hub that retains a strong local corporate base.
Passenger traffic at the five airports grew as much as 15% at Cincinnati in 2018, US Department of Transportation data shows. Austin traffic was up 13%, Nashville up 8%, Raleigh up 9.7% and San Jose up 9.2%."
"Delta sees an opportunity to capture share with its product and schedules, for example connecting more travellers to its global network, says Martin."

"Delta's strategy differs by focus city. It serves both its hubs and numerous spokes from Cincinnati and Raleigh with up to 80 peak day flights, while routes from Austin, Nashville and San Jose are limited almost entirely to hubs and other focus cities, Cirium schedules data shows. Flight operations peak at 28 in Austin, 42 in Nashville and 31 in San Jose this summer."
"A lot of the focus is just trying to, for example Raleigh, really understand where the Raleigh business traveller needs to go, the times they need to go, what's their travel preferences and then trying to figure out how we tailor our network to be able to make sure we have good connectivity," says Martin.
"Memphis, a former Northwest Airlines hub that Delta closed in 2013, is no longer considered a focus city, she says when asked. However,
she adds that the airline is watching the market for growth opportunities."
Hope this explained a few things