Hard to say, but the newcomer's briefing and the Tao of the IETF are
both on the web site. Maybe we need some text on the registration page
pointing to those and suggesting strongly that people should read them
before typing in their credit card number.
maybe the registration form should have a short quiz on material from
these documents, which must be filled out before the form is considered
complete. and if not completed successfully the prospective
registrant is warned that he may be wasting his money.