Who or what will the Arecibo message reach? The Arecibo Message was aimed at the globular star cluster M13, but as far as I read, M13 will move out of the original position and thus not be able to receive it. So, who or what will be able to receive the message?
The Arecibo Message was not broadcast with the aim that it would intercept with a notable astronomical object. Neither do we realistically expect that anyone will ever listen to the Voyager Golden Records.

Such symbolic gestures are simply vectors for public relations and education. We send these "time capsules" into space because we can, as a showcase of our technological achievements, and as a token of hope.


  "As the choice of frequency, duration of message, and distance of the
  target clearly shows, the Arecibo message is very unlikely to produce
  interstellar discourse in the foreseeable future. Rather, it was
  intended as a concrete demonstration that terrestrial radio astronomy
  has now reached a level of advance entirely adequate for interstellar
  radio communication over immense distances."
  
  -- NAIC staff (1975), http://adsabs.harvard.edu/abs/1975Icar...26..462





  "The spacecraft will be encountered and the record played only if there are advanced spacefaring civilizations in interstellar space. But the launching of this bottle into the cosmic ocean says something very hopeful about life on this planet."
  
  -- Carl Sagan