It's all in the marketing. You want the King? Done. All the Sox have to do is use any of the players they've traded away as examples of what can happen to your team when you get an ex-Sox player. Whenever the Sox trade away players, they can make their team better. They can even become the best player on your team, and at the very least, be a spark for better production from your team. The examples are endless. Sox players seem to be pure gold when they leave the Sox.
Either the team has no idea who a player is before they trade them away, or the player decides to show the team how wrong they were about them. Either way, it's a win-win for the team that gets them.
I think that the history of this happening to teams on the receiving end should add value to any possible trades the Sox make. We should be able to give them anyone for King Felix, and those players will probably make everyone wonder why we traded them away to get the King, or anyone you can name for that matter.
It would be interesting to have a team made up of just ex-Sox players, just to see how they would do. I say look out MLB!