I have been to FReeps in DC and NYC but I think the most effective FReeps are the ones that happen every week on the street cornors of America. You have to oppose these people every day and at every oppertunity. It has to be upfront and personal, one man, one sign makes a difference.
With that in mind, allow me to rephrase my point. Chapter leaders need to be aware that there are differing levels of committment among their members and need to keep it top of mind when they with they request to get out and FReep more often than their members are able. Continually pushing people to put in time they don't have is a sure way to burn them out and drive people away. They need to temper their urge to market every event as "you absolutely HAVE to be there" and save it for those times when an event is absolutely critical. Otherwise, for the serial events a good approach is "We understand if you can't make it but would love to have you!"
I'm not suggesting this is what happens in your chapter, but I do know it goes on in others.