Does the phrase "satisfaction guaranteed or your money back" make any sense from a grammatical standpoint?
It's missing a few words, like many marketing phrases which have to economize on airtime and/or print space and thus shorten understood sentences to "buzzwords" and "buzz phrases". It's equivalent to the complete and proper sentence "your satisfaction is guaranteed or else you'll get your money back". The term is so common that these missing words are implied in the saying of the phrase. It can be further shortened; "satisfaction guaranteed"; the fact that you'll get your money back if you aren't satisfied is so universally understood in English that these two words, "satisfaction guaranteed", are a "buzz phrase" for the entire sentence, which you can say in just over a second of air time.
Yes, it describes two possible outcomes:
- (your) satisfaction (successfully) guaranteed
- your money back (returned to you)
In other words, it says "I promise that you will be satisfied, or, if not, that you will get your money back".
That's if you take "guaranteed" literally as a pledge that you will be satisfied, and not as a condition of being under warranty. Otherwise, it makes no sense to add "or your money back" since that is already implied by the "guaranty". I think that may be what was bothering you about the phrase, but I may be wrong.