I seem to be seriously confused about DishOnline, and I apologize for my response above.
There is a Blockbuster@home section which appears to be all about programs from the BB@home channels, and viewing them online via a PC. I see no way of queuing any of these for viewing on my receiver a la Netflix. That is too bad because the BB@home user interface on my receivers is so ponderously slow.
The On Demand section is more flexible, with options to view on TV, view on PC, or record to DVR. I think garys is right in that all the PPV movies force you to "record to DVR".
So... To answer the OP's question, I think the way you do that is to go to DishOnline, click on On Demand, select Movies, and then "Watch on TV". There is an option to watch live, and also an option to record. I think all this is doing is scheduling a timer on your DVR to watch (or record) a linear channel to which you subscribe. I can also find free content on the On Demand --> Shows and also the Networks menu items, but these appear to be for viewing on a PC only.
So here's my own question similar to the OP's. Is there any free content on DishOnline for download to our receivers that is not a whole lot more easily accessible simply by searching our receiver's guide for upcoming programs?