If you make a sale, you've committed yourself to making the lie come true (or at least hiding it's lack of truth). Say goodbye to your development schedule and/or your tech support budget.

Of course, hardcore sales people who don't mind lying will cheerfully say 'all's fair in love and war, and no battle plan survives first contact with the enemy!'. Lots of business people love war metaphors because competition justifies all sorts of things, and when someone asks whether customers are the bombed out civilians in this scenario they can say 'it's only a metaphor, don't take it so seriously!'.

If it's a question about your product, don't, although it's OK to say 'were looking at it - and that's all I can tell you'. If it's a question about your company the answer is don't, but nor should be afraid to assert your privacy. If it's output rather than response to a question (eg a whiff of bullshit in your sales literature, I'd say avoid anything more specific than 'our product is the most awesome' that can't be justified.