Tree's, high rise buildings, new homes wired with rg-59, well intentioned adult children buying theyr elderly parents that new fangled tv box thingamajigger, " you mean its not wireless and you have to use cables?", I cant get ( any old public access station or obscure local station ) this channel?, not understanding that a dual tuner works the same as two receivers, the mentality of they are owed everything just because they called us, adding an additional tv after the job is completed, wanting the good old boys hunting rv wired up, his neighbor who has directv thats not working wants you to fix it for free, the family member or friend that swears how often the satellite goes out when the wind/rain/snow/ blows, completing an install only to have a majour storm come in and keep the signal from getting to the dish, heavy work loads, shoulder jockey's, chatty customers, kids, dogs, cats, roaches, ants, things best left in the dark parts of your worst nightmares.
Thats the obstacles.