Given how desperate LDY clearly are, a 20 year deal with FR doesn't sound too far-fetched. Again, if it was that profitable why aren't they still doing it?
FR built their business by specialising in finding desperate airports close enough to metropolitan areas who were prepared to spend vast sums of money to have/keep them flying from/to there as they guaranteed to bring
vast numbers of passengers spending money in the local economies if the price of the airfare was cheap enough. LDY clearly falls into that category.