I used to work at the local Best Buy and, like most big retailers, they had us pushing the service plans and other stupid add-ons (magazine subscriptions, credit cards, etc). While they never told us to lie, they'd often tell us to omit mentioning any potential negatives unless the customer specifically asked about it.
Best Buy employees don't work on commission, true, but of course they gave more hours to the people that managed to get more customers to sign up for service plans. There's nothing wrong with that. Now, most of my co-workers were honest people; it wasn't uncommon to see some of them give the customers faulty information, but it was usually out of ignorance rather than trying to purposely be deceptive.
There was a handful of people, though, that would tell outright falsehoods to customers to get them to get a service plan or what have you. There was one employee in particular that would sign people up for the magazine subscriptions without even asking then (the 'free' trial that they charge you for after the 8th week if you don't cancel).
Of course, since I worked Customer Service I was the one who had to deal with all of the angry customers. Easily the most stressful job I've ever had. On the one side I had customers venting their frustrations at me. Then, with the way Best Buy's hierarchy is set up (there were about 12 managers, all with the same level of authority and conflicting sets of instructions) it was chaos trying to figure out exactly what they expected from me. So, I simply stuck to the official store policy and, of course, I got 'spoken to' (but not written up, because they really wouldn't have a leg to stand on) for accepting too many returns even though I was following company policy to the letter. After putting up with that shit for two years, I'd finally had enough and quit.
I suppose I'm going off on a tangent here, so let me get back on topic. I think that, with the exception of a few people, most retail employees loathe using lying to people, even if only through omission. Unfortunately, the way the system is setup, there isn't really much of a choice. I was fortunate enough that I could afford to quit a job that I hated (and that was back when the economy was still relatively good). But not everyone has that luxury. If you have a family to support or are a student paying your own tuition (as a lot of my co-workers were) it's not really an option. When I was working at Best Buy, the only people there that seemed to genuinely enjoy their job, other than the managers, were the people working in the warehouse (away from the customers). Most everyone else just sort of begrudgingly accepted that things could be worse and did their best to bear it.