The Broncos sent third-year corner Cassius Vaughn to the Colts, and Indianapolis sent Fullback Chris Gronkowski back to Denver.
Gronkowski played in seven games for the 2011 Colts and did not have a carry. His primary function was to block. He was only on the field for 34 snaps.
In essence, the Colts gave up nothing, but what did they get in return?
Vaughn originally made the Broncos as an undrafted rookie free agent in 2010 and played sparingly in 2011, returning kicks as well as playing some corner. He did have an interception for a score. He started three games for the Broncos early in the season, but he struggled mightily and didn't see the field again as a corner.
Vaughn broke his fibula late in the season and was placed on injured reserve.
Trades are rare in the NFL, but this was a simple case of math. The Broncos didn't have a fullback and they did have a surplus of corners due to recent free-agent signings.
The Colts secondary is shallow and short on talent. They didn't address the corner position in the draft, and Vaughn provides them with an able body to help fill out the roster during training camp. He can compete for two areas where the Colts have needs: returner and corner.
This is a deal the Colts can't lose.
Gronkowski is a low-impact player at a low-impact position. Vaughn is little more than a hopeful looking for a job, but if he makes the roster at all, the move will have paid off. If he doesn't, the Colts didn't give up anything they'll regret losing.