I was thinking at how new members don't really benefit from being referred, and how they could gain something without it being purely monetary (ie. $1 off per cycle).
What if referring someone allowed them to adopt the same plan the referrer has? In this case, for example, someone who wants the $90/90days plan could get it by being referred by someone who has it, even though it is no longer offered publicly.
This would probably encourage word of mouth, for "secret" plans!
It would also avoid situations where you hype PM up to your friends, but then they can't take advantage of your awesome plan!
What do you think?