I'm fairly sure 95% of TVS are now HD tvs.
As far as HD service Directv and Dish virtually made it almost impossible since the Hopper and Genie launch to even know that SD option even existed in the past 5 years.
If a customer wants SD you really had to hunt deep for that option.
As far as Existing customer, well I don't know anyone personally with SD only equipment with Dish or Directv.
Certainly no one on Eastern Arc is SD.
Samsung Galaxy S6 Active
You would be extremely surprised how many SD televisions are still out there. 1/2 is the jobs require RF modulars to even be able to hook them up because they don't have A/V connections on them.