Many wrestling fans don't realise it, but the truth is, Wwe keeps obvious wrestlers away from Tna by not releasing them, so that they can't sign with Tna. Carlito is a very good example of a wrestler that they have kept away from Tna for a very long time. He has even requested release in the past, but he was "convinced" to stay.
So why exactly does Wwe do this? It's because a lot of the wrestlers that have worked for the company, know a lot of the ways that it operates. Now they wouldn't want these "secrets" leaking out into its competition.
Another aspect of this that many fans don't understand is the timing of when Wwe releases their wrestlers. Obviously Wwe can't just keep every wrestler they don't need on their roster, just so they don't go to Tna. That would cut too much into profits. So what the company does instead, is they release these wrestlers when their competition has just heavily invested in signing other performers, so that they have a hard time bringing these wrestlers into their company.
If you look at the new handful of wrestlers that Tna signed (Rvd, Jeff Hardy, Hulk Hogan, etc), they're all big name wrestlers. Meaning Tna has invested a large chunk of money into them. It's not exactly a trade having the world's most supreme wrestler, Hulk Hogan in your company. While Rvd and Jeff Hardy might not be as popular as him, they still are quite demanding as well because of their name value.
Pro wrestling fellowships have been using these methods for a very long time. Even Wcw used to implement this, back in the 1990s, and it's still used today. It's plainly a smart company move.
Wwe holding Wrestlers Away From Tna