The "Subway Theory"

I love fast food. Therefore, I observe much of what goes on behind the scenes of my favorite fast food joints. I even worked at a Taco Bell for a year when I was 16, and then for a Blimpies for about 4 months. One trend in fast food has been the surge in popularity of such fast food fares as sandwiches. Subway, Quiznos, and other regional restaraunts have surged in popularity over the last decade or so. Many point to the increase in popularity of a more healthy choice, and sandwiches are generally more popular. While I accept this has given the Subways of the world some traction and a way to differentiate from competitors, I do not believe it is primarily responsible for this growth. Neither can price be a primary factor. Generally, the sandwich fare is a premium in a market now dominated by dollar menus, although the $5 footlong promo is one of my favorite marketing strategies of all time, and has helped sales and profits tremendously for Subway. Yet, it is still not the cheapest. Can superior quality be the primary driver of the surge? Not really. Subway is the by far one of the lowest quality sandwiches you can get. The bread alone is cracker thin wrapped around cold cuts that are disturbingly all turkey based. So what is responsible for the surge in popularity for these kinds of restaraunts?
Here is my theory. It comes down to who the heavy user is, and who is the prime influencer in decision making when it comes to choosing fast food restaraunts. I would state that this person is more than likely a male, age 15-24 for most families. I was once this hungry young man, and I know that I consumed much individually and heavily influenced introducing my family and friends to much fast food. This is part one of my theory.
Part two: The demographics of fast food employees has shifted over the last decade in the US. Back in the early 90's it was very common for teens to work part-time jobs at fast food restaraunts like burger joints, taco fare, and the such. I would call these food prep jobs that included little customer interaction or even vision of customers since preparation is usually in a separate kitchen out of customer view. We know that these jobs have primarily shifted to low skill workers, commonly ESL hispanic workers, and that has worked out very well for all parties involved. With these jobs taken, have US teens quit working part-time jobs? No. They have shifted to work in jobs that benefit from their ability to communicate and serve their majority demographic.
Part Three: You now have the prime influencers and heavy users working in fast food restaraunts like Subway that require constant efficient communication with the local community. I propose that this paradigm shift led to the gobbling of more sandwiches over the last decade. Fast food is comfort food. Comfort food is food you are very familiar with. While I never ate at Taco Bell until I worked there, since then I am a regular. Such is the case with the sandwich shops. The surge of Subways popularity can be traced back to the sandwich artists themselves, and how they influence consumption.