Before you two, XH(gotta love that-state media service) and FB, get going, WAAS is independant of ADS-B just as TSO146 navigators are independant of ADS-B. There are a lot of people on this site alone that would gladly take WAAS availability over any other development available now.
Binghi, how about- Transport control
- Agriculture
- Prison systems
-Shipping
- Mom and Pop with their Bitchin Betty
- Delivery systems other than transport
- Equipment rental companies
- Goods monitoring systems
- State government toll companies
- Mining and exploration that only require first and second order surveying control. (Seismic comes to mind immediately)
I could go on, the list will be endless. All of these help productivity in small ways that add up to a huge national benefit. just as the freeway from ML to SY that has taken more than my lifetime to complete is helping productivity in no small amount and is provided free to everyone who wants to use it...not just the actual vehicles that actually earn the money by being able to get from point A to B in the quickest safest most efficient time available.
You know squat about DGPS, Binghi. It is not cheap and it certainly isn't wide ranging. If you must. Study about the augmentation signal that was transmitted through the JJJ network and who that service was aimed at.
EDIT- to add, just check out some of these google adds on the side of our posts to give you a better idea of what GPS is good for outside of aviation.
GOOGLE ADD