I use Pay As You Go. When you cancel your service, your service is credited with a per diem dollar amount for what ever time is left from your month. I currently have a $9.36 credit on my account that will be applied when I restart service this fall at the start of our winter sojourn. If I start in the middle of the month, I pay a prorated fee, less my account credit, and at the end of the month, I'll pay for the next whole month. If I cancel my service before the month is up, I get the balance as a credit.
PAYG is probably fairly lucrative for Dish. They have to keep X number of telephone techs online and that really is their only stake in our utilization. No equipment to keep track of, no antennas to install or repair and billing, for them, is a lot simpler. I "heard" that it was evidently lucrative enough that they ran all of their techs through a special RV training program. I used to use their online chat to avoid some of the misunderstandings, but, that involves more steps to get anything done. Lately, I just call and have only had one foul up...and that was because the guy got distracted and mistyped the zipcode for my new location to get the locals...that could happen no matter the contact method.
It is my understanding that a Direct TV receiver will only work with a DTV signal. The antenna, whether manual or automatic, must also match as the LNB frequencies are specific to each service. Aside from different satellites being used, their frequencies are also different. I don't know for sure if even the angle of the LNBs are different in relation to the disk surface...I suspect so, since their are different dishes for each service and I don't recall ever seeing conversion kits. Maybe someone a lot more knowledgeable than myself will chime in.