1. How often on television that matters/dichotomy is changing due to cord cutting and streaming, but argument still holds nationally
2. Ability to establish media relationships alone vs having to depend on a conference affiliation to actually garner any attention. (most of the middling to lower P5 would struggle with this.
3. The oldest, largest and most developed tv station geared towards just the school and it's programs alone. To a level that 3 of the top five college programs visited regularly the school to verify how they were able to it. Texas tried and has failed to reach the level of interest (reason because the church is international and connects people in a way that far exceeds what a football only interest could). Remember the ESPN has actually used BYU TV as a means to managing a few of their broadcasts.

Now to the nitty gritty

4. 60K plus seating at a stadium where a continuous 90% plus percentage of butts in seats at all games. Not talking ticket sales which continue to sell out, but actual attendees. This puts BYU firmly in top 25 attendance annually.
5. Willingness to travel anywhere to play opponents. BYU has had more neutral site games in NFL stadiums than any other program. Again brand awareness. Hard to avoid that when you are playing on the greatest stage.
6. Total athletic program ranking. BYU continues to flirt with the top 25 in Directors Cup which means that all of their programs are competitive not on a local or regional or conference level, but on a national level. This again means exposure and awareness by other schools in all parts of this country of the BYU brand.
7. The global nature of BYU itself means that majority of those attending are from other places which escalates the national viewership. There are literally tens of thousands of BYU fans who have never been to Utah. That enigma in itself is what causes surprise to teams back east or in the south when they see 5 to 10 thousand visiting BYU fans due to the homegrown local viewership. No other school has a national spread based on similar factors. There are other schools with national brand, but most need to truly travel when attending away games.
8. Coach Lavell Edwards has one of the most prolific and most accomplished coaching trees out there. This in itself still bears fruit both at the administrative level on down to players and recruits.

I could go on, but I think I have proven my point.