When conference realignment first took place a year or so back, the Mountain West was the subject of expansion, and a target. The MW had many talented football programs in its grasp, and some of those were lured away. Others, however, joined the group. One of these smart colleges was Boise State.
The Broncos were a dominant force in the WAC. But in order to gain more respect, a new conference was needed. The Boise State schedule when in the WAC wasn't impressive, so a move to the more competitive Mountain West was smart indeed.
Not only did this increase national respect for BSU, but the Mountain West accumulated more respect as well. As home of the Football Powerhouse and BCS contender, the Mountain West would more easily gain schools in later expansion.
Take today for example. The Mountain West is a much more prestigious conference resulting from the addition of Boise State. Soon, and maybe in the upcoming week, the Mountain West could take or even absorb the now crumbling Big 12. It could avoid a bad move in combining with the C-USA in a football "alliance."
A combination with the C-USA would not help the Mountain West because if the Big-12 and Big East were dissolved come 2012, that would pave the way for the MW to gain AQ status. Automatically Qualifying for the BCS could not be possible without the addition of Boise State.
BSU brought a massive fan base to the Mountain West, and if/when the MW take schools from the C-USA and Big 12, the conference's fan base will nearly double. If they play their cards right, the MW could double in size, from eight teams in 2011, to 16 in 2012.