I’m puzzled by the earlier comment that it’s rude to apply to more than 10 schools.
As with many things, it’s not always WHAT you do, but WHY you do it.
If one is merely applying to top-tier colleges to amass a brag list of acceptance letters, yes, that’s extremely inconsiderate on many levels.
If, however, one is applying to 10, 12, or 15 colleges of various levels (reach, safety, state, private, ivy) because his or her going to college is vastly dependent on financial aid package offered, that’s not rude, it’s survival. This is true given that one does not know how to compare the true cost of the colleges up front until the financial aid offers come, which is quite late in the process.
This latter scenario is what we’re facing right now. Survival.