The ability to easily create custom fields so we can have an easy way of tracking our exhibitors at events as well as making it easier when processing registrations in regards to credit card payment options! It also helps us run reports which makes managing attendance numbers much simpler than manually entering each attendee into their own spreadsheet or database (which was what I used before). We use this software mainly because its one stop shop where all attendees are registered together regardless if they paid via check / cash etc..