DS18 took the March SAT and last week started to get a noticeable increase in college mail. We found out with DD16 that the CB releases (sells) score ranges to colleges before scores are released to students.
Anyone other March test takers notice more college mail recently? I’m likely reading too much into this but hey, anything that gives a hint of good SAT scores I’ll take as a sign 
That’s a lot of wishful thinking on your part 
Your question assumes that in 16 days, CB has scored all the tests (my son took it that day too) batched and sold the high scorers list, and the colleges have had their mail houses address and bulk mail their mailings. Truly not possible.
My assumption is that the mailings are still based on the PSAT scores, and the colleges are trying to influence spring break visits. We’ve gotten more lately too. In fact, I’m in disgusted awe at the volume of paper that goes straight into the recycling bin.
I am going to agree with the PSAT score being the trigger. My son has not taken the SAT since December, and the Jan PSAT score release definitely unleashed lots of mail. There does not seem to be any rhyme or reason to the mailings.
It would be too late for spring break for us since today was the first day back at school after Spring break;-) We arrive back from our spring break trip to find a plethora of new college mailings, they had started to die down a bit from the PSAT mailings but now they are back in full force.
@Leafyseadragon you’re right that the time lines don’t add up and it’s likely wishful thinking on my part! I’m disgusted at the volume of college mailings too. I have to wonder how many scholarships a college could offer with the amount the spend on mailings.
After the insane amount of college mail dd16 got. I’m keeping all the college mail ds18 gets and weighing it May of his senior year.
Mine reduced greatly since the PSAT because:
I unsubscribed to student services (never had subscribed in the first place but of course CB ignored)
unsubscribed from each individual college that came in email, that I want interested in
No pickup in mail here - eager for May 10th to arrive!
D3’s mail has picked up in volume as well. She also took the March SAT but I think the uptick is due more to the fact that she’s a junior and it’s spring.
I haven’t had much mail from colleges after this March SAT, just some e-mail, but I didn’t take the PSAT, so that’s probably why
I am inclined to agree with the OP. My DD has also seen a significant increase in both direct mail and email in the last few days. The selectivity of the schools, and quality of the mailings, is different than the deluge we experienced after the PSAT as well. Lastly, my sophomore DS, who also took the PSAT (similar score to DD), but not the new SAT, is not getting much of anything.
@Hellofagal if you don’t mind sharing - what selection index did your DD and DS get on the PSAT? Also what state do you all live in? (assuming they are not boarding).