I've been a long time user at yodlee.com which powers the backend of Mint.com and other account aggregators. Yodlee gave up on the idea of trying to monetize the customer information they have. They instead reinvented themselves as the technology provider for all other financial institutions.

I am sure Yodlee.com is a profitable company but I do not think their investors will ever see much return on the 110 million dollars worth of investment since 1999.

If you take away Yodlee powered backend, Mint.com does not have much going on for them other than the subscriber base. If you have a hard time monetizing from the subscribers you have, It's just going to be a long painful ride for everyone involved.