Cockroach salad...

" After all, when some software has killed your PC do you really want free copies of the software that caused the problem in the first place. Cockroach in your salad, sir? Have some free salad. "

You know, I would have thought that, given that the offer was for more of the bad thing that caused the harm, your analogy should really have been written...

" Cockroach in your salad, sir? Have some free cockroaches. "

... but maybe you just find cockroaches really juicy and tasty, and consider salad repulsive?