A venture capitalist named Josh recently told a long but interesting story of Francis Bates (read more on page 1014 of this PDF download), who invented the flags that come on mailboxes to indicate that there’s mail in the box.
The story is an analogy for a company that Josh’s company has invested in, Gnip. I definitely do not understand what Gnip does simply by visiting its Web site. But Josh’s story, equating Gnip to the mailbox flag does help a little. 
