In terms of the recent history of AP, one reason for the courses’ popularity is that around the turn of the century, Newsweek started rating high schools based on the number of AP tests taken per capita as the sole measure of a high school’s value.

So naturally, administrators and teachers had a massive incentive to convince more students to take more AP tests, and hence prepare for them by taking more AP courses (though it should be noted that the students don’t need to get a certain score on the AP test to count for the rankings - just taking the test is sufficient, on the theory that schools should be challenging students).

So that’s what the signup emphasis is about. But, are the courses good for students? Two examples close to me:

SunSon, now 21, took AP Calc his junior (AB) and senior (BC) years. He got a 5 on both tests and ended up not having to take any math as a collegian - though he decided on a math minor and is taking his third and final college course in fulfillment of those requirements. He’s always liked math and it proved a good match for his interests.

SunLass attended a selective public high school which pushed AP a great deal. The freshman year social studies and science courses were AP Human Georgraphy and AP Environmental Science, two courses that were normally taught in a semester in high school but could be adapted into year-long courses at the AP level for freshmen. After that, most of the AP test curricula were available at various levels in her school; between AP US History, Government, Psychology, Statistics and a English class offered as dual-enrollment with the local community college, she ended up with enough credits to start college this fall classed as a sophmore, skipping the intro psych courses for her major. She is highly motivated, self-starting, and knows how to take time for herself and have fun with friends even while carrying a tough academic load - so in many ways, the ideal AP student.

Now: in any situation with high-stakes testing, there is going to be pressure to teach to the test and encourage student regurgitation. If a school loads students up with tons of courses, there may be not as much learning going on.

I’d encourage any student to give at least one AP course a try early on in high school, in a subject that interests them, if they have the option open. Hopefully by the time senior year rolls around your student will have some idea of the workload involved and be able to gauge how many and which AP courses would be good to take. It’s a nice option to have for a student who is precocious in one area, so they can explore it more in-depth - I tend to think a lot of high schoolers are good enough in at least one thing to be able to take a crack at college-level work in that area before graduation.