I did it for about a three months for Time Warner cable. It was funny listening to people rant, when they already had their service. The service sucks, etc. ... My favorite were the people offended that I didn't know they already had it. The killer was sitting at a desk for eight hours a day.
Now, door to door is another thing. Calling someone at home is one thing. Knocking on their door is another. People just want to kick your ass. I can't really blame them, though. I had this contracted gig through the city water department. It was water conservation stuff. We had to canvas an area going door to door with pamphlets, low-flo heads, and bladders for their toilet tanks. I had to do these stupid roleplays with supervisors for a week. I almost quit over that along, but I kept going. I can't tell you why. Well, I had two days canvasing a really shitty, low-income housing area. "What chu want?!", was a common greeting. On the first day, some dude thought I was there to repo his car, so he came to the door with a shotgun. On the second day, I just left the shit on their doorstep and quit at the end of the day.
I ended up taking some of the stuff home to try for myself. The showerheads sucked. It's bad enough, if you don't have a water softener, in Florida. It's worse with the lo-flo heads. They pretty much sprayed a mist. It was pretty pointless because you had to stay in the shower forever to rinse. The toilet tank bladders caused you have to flush the toilet 3-4 times, to send a turd home.