The hub 'n spoke system is highly effective at funneling passengers from a small market into other small markets, or anything else for that matter.
For example: There probably isn't enough O&D pax a day to justify flying a CRJ between Shrevport, LA
and Tri-Cities, TN
/VA. But if you route that passenger through Atlanta, with passengers coming from New Orleans, Birmingham, Daytona Beach and so on, then you can get your plane to Bristol. Same principle is also at scale for international flights. On its own Atlanta might be able to support one flight a day to London, but with all of the feed traffic it can now support three flights.
The downside is that there is an increased chance for delays to negatively effect the system. In order for the hub to work all your inbound flights need to arrive at relatively the sametime, and your outbounds need to leave around the sametime as well. Physically we know that this is impossible. In order for that to work conditions usually need to be pretty ideal to facilitate one full bank to come and go. When the weather goes south, slowing down airport operations, the entire bank is in jeopardy. It can also effect the entire system, depending on how isolated that particular hub is.
As for point-to-point, the main advantage is that there are more direct and non-stop services between city pairs. As an example Southwest (America West also flew this at one point) has several daily flights between SMF
. Neither station is a large operation for Southwest mind you, but enough demand exists to warrant such service. Plus passengers do not have to connect via SFO
, or just fly SMF
and drive the rest of the way to Orange County.
The downside is that point to point really doesn't work for smaller markets. You can't get a non-stop flight between SHV
because there is not enough demand to begin with. There is certainly a lower limit as to city size which will allow for a point-to-point flight. There also needs to be some major draw between the two cities, like tourism or major businesses.
With that all said you still see more airlines running a pure hub and spoke model vs. a point-to-point model. Many airlines, even some majors such as Delta run a variety of point to point services. Despite having the mega-hub at Atlanta, Delta runs (in addition to what Song flies) a fair number of non-hub flights flown both by mainline and connection metal.
Even the European LCCs use "bases" to run their networks. An airline would probably not run Bristol-Malaga if neither Bristol nor Malaga was not already in their network from one of their bases.
But what makes a network p-t-p or hub based is ultimately the ability to connect to one flight or another.
Stop drop and roll will not save you in hell. --- seen on a church marque in rural Virginia