I have to disagree; if it was
that easy to replicate Mint's success, how come Mint can worth that much of money, and why people are using Mint's service instead of
Your-Mint-Clone?
Your comment reminds me of the remark ( either here or on reddit, I can't remember) that StackOverflow is easy and can be cloned in a week, because the underlying technology is not hard to replicate. What you forget is market often pays a premium for the database, not the technology. Getting the technology to setup is easy, getting the subscribers, is not.