The owners of Cibao Airport were actively trying to get Air Europa to have a flight or two to Madrid. They went as far as to get help from the Dominican government to make that happen and the government agreed to pay the airline the seats that aren’t bought in order to ensure the flights will be profitable, at least in the beginning. If it wasn’t for the DR government getting involved, I doubt they would had ever flown to Santiago.
The airline is guaranteed to make a profit on every flight in the Madrid - Santiago - Madrid routes. In a way this is like when the current Cibao Airport was built. The owners were expecting that the airport would serve mostly Cibao farmers, free trade zones and other factories that export. They never thought there was a Dominican passenger demand, except that the Dominican diaspora in and around NYC has a large presence of families from the Cibao region. Further back in time it was even more. That’s one of the reason on average the Dominican population in and around NYC is lighter than much of the Dominican population in the DR. You also see this when things such as a Dominican parade takes place and notice the spectator who are mostly Dominicans.* They were surprised with the Dominican passengers response to the Cibao Airport and to this day most of its flights are to NYC. That happened by chance, but usually private business isn’t aware of the latent demand and only gets involved when the government enters and guarantee them to make money at first. Then they notice what they didn’t before.
* Any New Yorker that has been living in the city since the 1960’s or 1970’s will confirm that on average Dominicans arriving to NYC were lighter and have been getting darker as tine went on. It was also very rare to see a black Dominican in places like Washington Heights in the 90’s, when it already was the cornerstone of the Dominican community.