With the #9 and #13, it allows the Jets to move back from one of those spots. Let's say for instance, the Jets trade away the #9... and in return get the #22 pick overall, plus maybe a 3rd rounder.
The Revis trade them looks like this:
Tampa gets Revis.
Jets move back from #9 to #13, get the #22, a 3rd this year and a conditional 4th next year. That's a great haul, and why the #13 is worth way more to us than getting a "lotsa picks". It puts Idzik in the drivers seat to leverage the worth of the #9 and #13 for quality additional picks, and HE gets to dictate what he wants, when teams come to him asking us to move back.