This program, along with the fact that Telefonica, the incumbent operator, decided years ago to concentrate its efforts on deploying FTTH (all that's really left right now is to complete rural areas), and having an incentive of doing copper switch-off, means that each year there are more and more villages (even really small ones of, say, 10 people) covered by fiber. Telefonica hopes to have 100% FTTH coverage by 2024 (right now we're on 80%).
Orange is also another operator which also deployed lots of fiber both by itself and through this program for rural areas.
The competitive telecom market in Spain and also the regulations appear to have also been a factor in this transformation.