Last week brought a couple high profile announcements in the tech world. Google announced it would shutter Google Reader on July 1 and Dropbox announced it had acquired the hugely-popular-but-how're-they-gonna-make-money Mailbox app. At face value, these were two separate and unconnected events but they bear a lesson for all of us to take to heart: Running a sustainable business requires generating sustainable revenue. Charge money for what you create.