I'm sure they harp on its necessity in marketing courses all the time (I don't know, I've never taken one) but the unique selling proposition is one of those necessities that regularly gets ignored even though everyone espouses its necessity.
Too many of the briefs that float around the typical agency are full of clichés and "me too" product benefits. If you're a creative reading this, I know that you feel like a voice in the wilderness complaining about this; I know that you've tried to challenge your account team or client to tell you what's different, what actually matters about the product you're advertising, and I know that they've all come back to you and said, well, um, nothing.
Under these circumstances, if you're lucky the brief you're faced with boils down to, try to make it interesting, but we don't have high hopes. If you're unlucky, it's make it interesting and we have very high hopes.
The issue seems to be that the world is full of products that are all approximately the same. Clients tend to be bad at thinking about their products with any kind of realistic perspective (i.e., how consumers think about them) but they're also handed products to sell that are basically the same as their competitors. Apart from Steve Jobs and... well, I'm sure there's got to be someone else, no one is thinking about developing unique products that consumers actually want and will line up for. Maybe that's the nature of early 21st century market capitalism. There's a lot of cut and paste from whatever the competition is doing.
I point all this out selfishly, because it affects what I do. I've been asked too many times to make people "out there" care about products that no one "in here" seems to be terribly passionate about.
Passion comes from an emotional truth, not a list of bullet points of features written by engineers or accountants or programmers. Maybe it's arrogant, or simply unusual, but passion means standing out, being different, not caring that someone else may disapprove.
And if I can feel that passion from you when I'm getting briefed, then my job isn't necessarily any easier, but I know it's going to go in an interesting and above all real direction.
If I can't feel it at the brief, then it's my job to make up the reason that anyone should care.
And if I sound cynical about that, it's because I once had an ad killed because one – yes, one – grandmother in rural Saskatchewan wrote a letter of complaint. It was one of those times when I'd found a reason for people to care, found a funny/emotional way of connecting with people, but because it was a purely creative solution, no one internally but me felt the passion. It was easy to kill the ad and replace it with one that wouldn't get complaints, an ad that wouldn't emotionally connect with anyone, an ad that no one would really notice.