This has been a great thread, and I'd like to add my thoughts as a non-commission salesman:
I can totally understand the salesman's reaction - if I were on commission, I'd be pretty ticked that someone came out of the blue and basically sent my customer home to think more about it.
But as a salesman who generally doesn't work on commission (I make well under 10% commission, only on the product protection plans, and unless it's a high-priced item, it's honestly not really worth the trouble), it *still* ticks me off when someone who thinks he knows everything just butts into a conversation I'm having with a customer because he thinks he knows better than I do. He may very well know more about the subject, but it's like coming in halfway through a movie - you've missed a lot of backstory - what's the point?
At our store (I work for a national chain) we sell replacement plans which actually replace an item should it become defective. I took advantage of this when I bought a laser printer last year. It refused to feed paper, I received a refund, and was able to buy the Epson R1800 that I've been wanting for a long time. Yes, I use that story when I sell my plans, and even though commission selling isn't my main money earner, I find it hard to believe that there are still people who are just so distrusting of *any* salesperson that even mentioning a plan is an automatic "Oh no, I never get those" without even thinking about it.
I'm not one of those cheating, lying salespeople that people on here have been talking about. When I don't have what the customer wants, I'd rather send them somewhere else to buy what they *really* want, than to buy it from me. Example: I'm about to buy a Mac Pro (my first Mac), and I've sent 2 people out of my store who came in wanting PCs, but given what they told me, it sounded like a midrange iMac would suit their needs better, so I said so: "Go over to CompUSA and check out their 20" iMacs, I think it would be a better fit for the graphic work you want to do, than the HP PC you're looking at here."
If I were solely on commission, I seriously doubt I'd do that, because I'd *need* to make a sale. In my position, however, I can afford to really help my customers get exactly what they need and/or want.
-Bryan