ryantxr

It is easy to set up an event in Facebook.  It is even easier for someone to say they are coming.  They just click the RSVP yes link and presto they are registered for the event.  If you are doing a birthday party or some private personal event, that's fine.  But if you are doing a business event, you should not use Facebook events to capture RSVPs.

The main reason for this is that you do not get any data from facebook.  Services like Constant Contact, EventWax, EventBrite, Upcoming and the like allow you to capture names, email addresses and some other data if you wish.  Facebook has no means to get a list of email addresses from an event.  You could go to each person's profile and get their email address if they share it.  But that could take forever. 

The way to run a professional event is to use a service that lets you get the data for all the attendees.  This lets you easily pre-print name badges, send follow up emails, and do all sorts of other things with the data.  These services also let you print tickets.  You can require that the guests print these out and bring them to the event. This can ensure that only registered individuals are allowed in.

No doubt using one of these services is a bit more trouble for the user.  But it might be better.  A person who takes the time to do this is more likely to show up.