The 757 used by the airline can reach gateways with far better market potential. Take a look at the chart for a 4,000NM range from RAI, the airport code for Praia. Even if the 757 wasn’t going to use its full range, there are many other cities that would seem to have better potential.
But apparently there is a Cape Verdean community of sufficient magnitude to justify the route. Besides a new route always creates its own economic momentum.
For those living within easy reach of PVD, it might be of interest to know that Cape Verde offers some of the most pristine beaches in the world. In the “old days” when South African Airways used to refuel on SAL (another Cape Verde island) crew changes were popular because the beaches are spectacular.
So when winter comes to New England (almost immediately after Thanksgiving) the locals now have an option other than Florida for warmth and a tan.