The best bang for the buck in the Draft has always been in the 10-15 slot - last year Alualu, Graham and Thomas all went there and have had excellent rookie years; in 2009 Crabtree, Orakpo and Cushing went in the same area (two of them making the Pro-Bowl in their rookie years); in 2008 Mayo, McKelvin, Clady, Stewart were drafted one after another; and in 2007 you saw Patrick Willis, Marshawn Lynch, Darelle Revis and Lawrence Timmons (two of which are the very best at their positions in the game) were drafted in that part of the Draft.
In that spot, two things happen - great players can drop if there's a run on certain positions; or you can draft someone who you really like a few positions ahead of where they might normally have gone without too much worry about paying them more than the position normally earns in terms of the Draft pay scale.