Why not go for services that have bot One Stop Destinations and Hub Spoke.Airline connections as follows:
Town A-City A- City B- Town B (Change of flights)
Town A-Town B- Town C (No Change)
This could add alliance partnerships as well. Say
Airline A from Town A- City A (Hub of Airline A or Alliance Partner )-Town B
Revenue could be shared on basis of miles or tickets sold.
Small airliners can get increased wealth and major Airlines get more PAX on hyper competitive routes.