We decided not to make email addresses unique, and it has caused a number of problems.

I'm not sure how much you know about DB calls from scripts, but basically it seems like they implemented a few functions where they return information based on the first row found in the DB with a given email address; So, if you implement non-uniqueness, you may encounter situations where pieces return the wrong person information because it found the first row (or a random row, or something according to hidden logic).

I don't know too many details because I am not the online lead here - just RE.  But I definitely have heard comments about this.

Thank you, Kirk.  I've been looking for feedback from people who have actually crossed this bridge.  I wasn't aware of that issue but it makes sense.

Ray Mauder:

There is a small group of RE users out there who also are involved with Convio.