I've never really thought about it, but I suppose there's no reason you can't to do it.
A burger's components aren't that different from what you would find in certain Mexican dishes, and I don't think anyone would have a problem with you putting salsa on something like a taco.
If you're going to put salsa on it, you'd better eat it with a fork and knife lest you want your hands to be drenched in salsa you filthy savages.
I douse my body with salsa every night before bed. It's the only way I can fall asleep anymore.
It's the only thing I feel at all anymore...