Mailchimp client sites capture people's birthday on their signup form for their mailchimp emails, usually to send automatic birthday wish emails. Mailchimp use

Mailchimp client sites capture people's birthday on their signup form for their mailchimp emails, usually to send automatic birthday wish emails. Mailchimp used that data for analytics. http://blog.mailchimp.com/new-birthday-field-for-signup-forms/ http://blog.mailchimp.com/new-birthday-field-for-signup-form...