@NCKris Most Semi Finalists do make Finalist, but only 2,500 of the Finalists are National Merit Scholars. Another 5,000 or so get scholarships from various corporate entities. Finalists and Semi-Finalists also get different scholarships from some colleges, with some colleges offering full tuition. The national Merit Scholar Scholarship award is only $2,500. I assume that your son is not just a finalist, but a National Merit Scholar.
NMF is a big deal, even though 90% of all NMSF make NMF, because it means that not only did the student score well on their PSAT, but they also did well in school, wrote a decent essay, and did reasonably well on their SATs. Being a NM Scholar is a bigger deal, since, as I wrote, only 1/6th of all NMFs achieve Scholar status (which would be, this year, only about 0.14% of all the kids that did the fall 2017 PSAT).
Being a NM Scholar is very impressive, however, by the time it’s announced, students have already been accepted to colleges, mostly know their financial support, and are already thinking about college. A Finalist status is enough to be eligible for almost all the big scholarships that are associated with National Merit, so a Scholar status does not make a big difference, financially. So the National Merit Scholarship, while prestigious, no longer affects acceptance, the amount is relatively modest, and it’s already moving into the category of “High School Things” which are being relegated to the past. That’s why it sometimes flies under the radar.