Sounds like there is more to this story. If they are adding hundreds of new clients, why are folks heading for the door?
You need to reach a critical mass in users before you can take action on certain potential profit centers. It's different for every industry and every business, but there's some things that would be more trouble than they're worth at 25k users but start making you a lot of money at 100k users.
Also, Mint never IPO'd; they sold to Intuit (the "old" competitor in their field, with Quicken) for about $200mm. Nice money, but it was argued by a lot of people that they could have hit $1-2b in an IPO. We'll never know.