From what I understand, Dish owns Sling TV. They started it to attract the under 30 crowd that is not signing up for cable. They are likely to raise the rates if there is a mass exodus from cable/satellite to Sling.
http://www.cnet.com/news/sling-tv-everything-you-need-to-know/
For me, I got tired of paying for all the things I don't watch just to get ESPN and the SEC Network. We dropped Dish satellite service that was costing me $128/month and subscribed to two devices on Netflix for $8/month. That satisfied my wife and kids for programming.
I was missing sports and I have to put up an antennae to get the digital signal, so Sling is a great option for $25 and we get CNN for news. It may now be as good as the programming for $128, but for well under 1/3 of the cost, we won't miss Fox News and HBO that much.