I've heard NCSA is quite good when it comes to many of the sports where there may not be much repeated exposure to large groups of coaches. Take swimming - I've heard "times" are sort of the sole measure (they're not really looking for grit or the grinder when it comes to the 50 free). Throw in the female gender and perhaps their are some programs that are looking for solid candidates who have expressed a sincere desire to compete at the collegiate level.
Moving over to baseball, RC's don't really have to go snooping around NCSA trying to find candidates as they can head over to some PG tournament and find dozens of kids who might fit the bill - then repeat the following week.
I do agree with the possible motivational component. This could easily be the case where the kid is not some Power 5 prospect (very, very few are) and shelling out some bucks to create a "carrot" can be well worth it if the only payback is a solid high school transcript. I think when push comes to shove, NCSA cannot simply be relied upon to get RC's to your doorstep, but I can see it being a component and probably costs around the same as a high end bat or glove.