Third tier rights are a giant bucket of various items. The B12 is not the only conference whose schools are paid for these rights.
See this link on WVU's contract, which pays them an average of ~$6.7M per year:
http://wvmetronews.com/2013/07/11/img-earns-tier-3-deal-for-80-million/
"The contract covers television rights for one nonconference football game and several men’s and women’s basketball games not selected by national networks, radio broadcast rights and coaches’ shows. It also includes online rights and various advertising opportunities including signage and sponsorships at all WVU athletics facilities."
The only thing in that list of rights that B10/SEC/P12 schools don't retain the rights on is one non-conference game per year. The coaches shows, radio shows, in-stadium signage, etc., are all being sold by B10 and SEC schools at similar (or higher) rates as B12.
Iowa was paid $5.8M by Learfield in 2013-14, and will be making over $8M by 2025.
http://www.thegazette.com/2011/09/0...ts-athletics-department-more-than-5-8-million
Ohio State receives over $10M a year from IMG, which also notes that Florida and Alabama get $9.4M:
http://www.bizjournals.com/columbus/stories/2009/03/30/daily4.html
Note that the OSU article says: "Most of IMG’s other deals include some level of TV rights that can be worth another $1 million to $2 million a year."
Which is consistent with the value of a single college football game, i.e., the single non-conference game that B12 teams retain the rights to. So, the B12 additional TV rights boils down to a single non-conference game, generally the absolute worst game on the schedule. What do you think the value of this year's WVU-Youngstown State game is on the open market?
Last year, WVU had a game against Liberty televised on Root Sports Pittsburgh, a regional affiliate of FSN. How much do you think Root Sports Pittsburgh paid for that game? I would be absolutely astonished if they received $1M for it, something like $300k sounds more likely.
The UNI/ISU game was televised on Cyclones.tv and available to pay to watch on the Cyclones web site. How much actual dollars did that game net for ISU?
Bottom line: B12's third tier TELEVISION rights are worth roughly $1M per year over the other conferences.
And their other third tier rights are generally worth less since they are low-population areas.