I have uttered this phrase only once out loud to someone. Knowing exactly what I was saying and why, she responded, "That isn't fair." In a sense, it wasn't, and it can't be. It isn't fair to tell someone you love them so that they understand without saying it explicitly, and it's never fair to tell someone you love them if they won't, can't, or aren't ready to understand what you're saying.
"As you wish" is the phrase Westley, the farm boy, utters in The Princess Bride by William Goldman every time Buttercup asks him to perform some task for her. What he is really saying, though, is "I love you." Eventually she climbs aboard the clue boat and the plot of the book gets moving.
There is also a movie.
When saying "I love you" is hard or inappropriate, "as you wish" is there to the rescue. This is the phrase I think to myself when asked to perform some task that I don't want to complete by someone I know I can't refuse.
"As you wish," I think to myself. And the task gets done.
An important theme in The Princess Bride is that life isn't fair. It is appropriate, then, that this most unfair of phrases gained its significance and, therefore, its unfairness, from this book/movie/modern fairytale.