A few weeks ago, my tooth fell out (on a cross country flight no less). I managed to get home and then eagerly put some Anbesol ("for oral pain relief, dentist strong so the pain is gone!") on the hole. Yes, that was my screaming you heard all the way from here.
The next morning, my dentist explained that not only doesn't Anbesol work on exposed nerves, it makes them worse.
You can read the label all day long and you won't see that mentioned. But hey, they made a sale (one sale).
Or consider this item on Amazon. How big do you think these "mixing bowls" are? The reviews point out that the smallest one is not big enough to hold an egg. Does that change your perception of the item?
Why not tell the truth? Why not call them "mini bowls"? Why not change the label from "toothache relief"? (Technically, it's not a toothache if you have no tooth, okay, thank you Mr. Lawyer, that's exactly the sort of weaseling I'm talking about.)
There are lots of things you can do to make the sale. They often are precisely the opposite of what you should do to generate word of mouth. I know, you can't have word of mouth unless you have a sale, but a sale that leads to pain is hardly worth it.
My rule of thumb is this: every person you turn away because your product or service isn't right for them turns into three great customers down the road. Every bad sale costs you five.