I don't know about 100M, but I can definitely see how Mailbox is worth a lot of money to Dropbox.
Dropbox has always been a company that stood on the quality of its product. It doesn't have the most features (that's probably SkyDrive or Google Drive) and it's not the cheapest, but it works insanely well and it works everywhere you want it to. That, and the headstart they had, is what put Dropbox where it is right now.
Mailbox is a quality-first mail app that fits with Dropbox's quality standards, and it allows them to take their first step into the "feature-rich web storage" field without trying to build out an office suit like MS Office or Google Docs that they clearly can't catch up to. This was a chance to buy their way into the mail game, with what some people would consider the best mobile mail app in the business.
Dropbox has always been a company that stood on the quality of its product. It doesn't have the most features (that's probably SkyDrive or Google Drive) and it's not the cheapest, but it works insanely well and it works everywhere you want it to. That, and the headstart they had, is what put Dropbox where it is right now.
Mailbox is a quality-first mail app that fits with Dropbox's quality standards, and it allows them to take their first step into the "feature-rich web storage" field without trying to build out an office suit like MS Office or Google Docs that they clearly can't catch up to. This was a chance to buy their way into the mail game, with what some people would consider the best mobile mail app in the business.