What’s the deal with these admissions consulting services?

I’ve come across multiple sites offering to help “gain admission to service academies” with very steep price tags…anywhere from $2k for interview coaching all the way up to $10k for comprehensive coaching, essay help, etc. I’m wondering how common these services are among accepted applicants and if USAFA admissions can identify applicants who come from these programs; if so, how that sits with admissions panels if they can tell mom and dad shelled out $10k to give them an advantage.