Hi grrymarkley, HughesNet does use some compression techniques mainly to make the system perform better but it is no magic thing that will allow you to get 3 times data on the internet for the price of one. Data doesn't work that way. There is some dead space in transmissions and downloads but nothing like what you were told can be reduced. At least not currently.
Basically, if a file or web page is "x" amount in size then you will be charged "x" amount of data against your usage. Again, maybe some small savings but nothing near what you were told by sales.
Also, things like streamed video files are already compressed so any small savings there is pretty much negated.
Welcome to our community! Our sales agent was right to tell you we do utilize compression techniques. You can read more about how the service works here: https://www.hughesnet.com/why-hughesnet/how-it-works
We would like to note that compression does not mean truly unlimited. The fact that you ran out of data in a day does concern me and I think it is worth taking a look at what is connected on your network. Do you have a DiSH or DirecTV set-top/DVR box in your home?