There are few people who go without entertainment on a regular basis, as society has developed to a point where almost everyone has some downtime. Sure there are many options for entertainment, but watching television seems to be the default choice for most people. This is why all of the top cable and satellite companies have put in tons of effort to try and prove to customers that they are the best option, as quite simply it is a lucrative business. You can see the ongoing arms race over at http://www.cable-tv.com/directv-vs-cable/ where it seems like neither side of the fight is ready to give up.
The bottom line is that once DirecTV releases a new feature or adds a few channels, the cable companies are usually quick to do the same. It goes in both directions of course, as DirecTV cannot risk falling behind any of the cable companies either. The reason they compete so much is that DirecTV is available all around the world, while cable companies are limited to local areas where they have established service. This means that cable companies usually do not have too much competition within their ranks, since companies do not expand to the same areas most of the time.
However, DirecTV only requires a clear view of the sky so has no limitations based on distance or network setups. Their other unmatched advantage comes in the form of football fans. Most networks carry the popular national stations like ESPN and NBC so there are tons of football games on every Sunday on all services. Yet DirecTV takes this even further with the exclusive Sunday Ticket package which makes sure that hardcore fans can see every single game and never risk missing their favorite teams or players even if they are playing games that are less popular overall.