Can someone please explain the economics behind this deal? Congrats to those involved...but at the end of the day, this just doesn't make much sense (to an outsider at least).
A portion of Dropbox's customers have grown accustomed to paying for the service. I believe those are Mailbox's future customers. Mailbox should be a premium add-on to Dropbox.
Even if the Mailbox add-on is priced at $50 a year, if only 1 million of Dropbox's customers subscribe and they stay with the plan for two years, Dropbox will have recouped its investment.
I believe that providing features like this add to the Dropbox brand. It's about adding infrastructure that the OSes are leaving at the wayside. In the same vein, I would like Dropbox to add RSS & and photo/video/music sharing backends that client apps could tie into.