> Beyond cost, I was also frustrated with having to make sure my database was always in sync with MailChimp and the audience schema they enforced. Could you ex

> Beyond cost, I was also frustrated with having to make sure my database was always in sync with MailChimp and the audience schema they enforced. Could you explain why this was such a problem? It would seem like this (API to submit data) is the sensible way to balance the cost against the security concerns raised in the other comment. Does mean engineering and sync issues which your solution does address in an interesting way.