Now they are doomed to work to the end of their lives for big corporation. No one will give them a dime if they ever want to work independently again. In my ex

Now they are doomed to work to the end of their lives for big corporation. No one will give them a dime if they ever want to work independently again. In my experience, ($700M sale to Google in particular) that's just not true. It's quite typical for acquisitions to include either earn-out provisions (you must work for the acquirer for N years or you forfeit some of the purchase price) or retention bonuses (work for N years to earn an additional $X million). Every investor expects these outcomes; nobody would be surprised or put off to hear that the Sparrow guys are locked up for N years, and nobody I know who invests would view them as damaged goods as a result. As for Sparrow users being the losers; there are lots of fish (future email clients) in the sea. The popularity of Sparrow is evidence of a market need. Whether any email client author can make real money meeting that need is another question.