with a school like Oregon, I can buy the same "O" shirt in dark green, kelly green, black, silver, white and yellow (all official colors).....that is just one shirt. I can buy a mascot logo shirt in those same colors. That is about 12 options with just the most basic of shirts. http://www.fanatics.com/COLLEGE_Oregon_Ducks_Nike

For a school like Georgia, I can buy a "G" logo shirt in white, red, black and gray. Same with a bulldog logo. 8 options. http://www.fanatics.com/COLLEGE_Georgia_Bulldogs_Nike

Boise State: royal, orange, gray, white.....more options, more sales.

With BYU, the good Nike stuff is limited to navy blue "y" logo shirts. The sailor cougar mascot logo is not available on any Nike clothing on fanatics.com right now ( http://www.fanatics.com/COLLEGE_BYU_Cougars_Nike ).
So basically I can get one navy blue stretch Y shirt. If they sold it in royal, black, gray, white, etc. I would buy them, but right now, I have a couple of different stretch Y Nike shirts (cotton and dri-fit).

Now do the same for shorts, hats, polos, etc. and it is easy to see why BYU is not near the top 25. I spoke with one of the marketing guys once and he said that the administration really wanted to limit the use of royal blue and only wanted it as part of the "classic collection" (or some other similar name).