Even the cable companies are getting wise to the consumer tactic of threatening to switch, just to get a discount. The cable companies do tend to extend some offer once or twice, but after that, increasingly, they're saying, "Go ahead and switch," knowing that just as many of their competitors' customers are playing the same game with their competitors, and will therefore be heading back their way, leaving the additional revenue that they make from those customers who in the end don't really switch as additional revenue, enjoyed by both competitors in their own respective measures.
One thing that the cable companies are doing is giving you discounts whenever you add more services, i.e., adding on telephone service. I don't know if DTV does that, and don't even know how many layers of service additions DTV has. They don't offer telephone service, for example, so there isn't much for you to add, I suppose.