For the past couple or event registrations we've had spam bots sign up and take valuable registrant spots. When contacting customer service there was no constructive help on how to avoid this, expect to put a captcha on our site for when people click a button to LEAVE our site. This user experience is a terrible idea and would deter registrants.
With that suggestion from a service rep. it seems like Constant Contact should have the option to add the captcha to registration forms. or have a spam filter. I'd like to suggest that or if other people have solved this more elegantly.