The sellout streak has had help from boosters along the way. But if it was so easy to sell out a 90,000+ stadium (or smaller ones for that matter), shouldn't everyone be able to do it?
In the CFB world of facilities arms races and keeping up with the Joneses, you know other schools would love to sell out their stadium every game if only they could. But you need crazy levels of fan support and, occasionally, well-heeled boosters to pull it off.
The next closest school is Notre Dame and they're roughly 12 years or 100ish games behind. Oregon is 140ish games behind the Domers. Couldn't even tell you who's at #4. Point being, NU fans deserve a lot of credit for supporting the team through thick and thin for damn-near 400 straight. A lot of good-to-great teams in there but plenty of clunkers too.