A recent article on New World News makes the proposal "SL needs a user-to-user karma system like Reddit".
Now, I would be lying if I didn't say I want to finish that sentence "... like it needs a hole in the head."
It's not that the idea is intrinsically a bad one... Wagner James Au makes a reasonably persuasive case for it. But he hasn't persuaded me, for two main reasons; firstly, I just cannot see a way to prevent such a system from being rigged, gamed, and otherwise manipulated. It's been tried before (before my time, obviously, I'm such a newbie) with dismal results; Mr Au thinks safeguards could be put in place to make the system safer and more reliable... I am not convinced. In my experience, any mechanistic system like this is open to exploits; the ingenuity of the determined abuser can't safely be underestimated.
My second objection is that it is a mechanistic system, and that a person's reputation and reliability aren't easily reducible to a simple numeric "+1". In my time helping out at Oxbridge, I've tried to make a positive difference, and I might easily have earned a "+1" from half or more of the people on my over-stuffed friends list. Does that make me a better SL Resident than, say, someone like Tali Rosca, who more usually keeps to herself, building, scripting and developing? Tali has always been kind and patient with people who ask her questions - picking her brains about sculpted prims was how I got to know her - but she doesn't so much go out of her way to provide advice to the new and bewildered. So, she might not rack up as many "+1"s as someone like me... but, when it comes to the question of who is best to seek advice from - well, I will do my honest best to give help, but my honest best is a lot worse than Tali's, because she knows so much more than I do. All other things being equal, then, I am likely to wind up with a better "rep" than Tali, while still deserving it less!
What makes a reputation? Is a well-meaning but naȉve helper-out as valuable as a knowledgeable curmudgeon? Do you get your "+1"s for being kind, or helpful, or funny, or what? I know people whose judgment I'd trust on all sorts of matters, no matter what their personalities are like; I know others to whom I would give the shirt off my back, but whose advice I wouldn't dream of following.... The "karma" system, I think, expects all these different factors to cancel out over time, leaving people with a number that (very loosely) expresses how well- or badly-regarded they are.
I'm not convinced. I think the numbers are too much of a blunt instrument. You see someone with a "+99" or a "-47", and you may realize that they've done something to deserve that rating - but you don't know what. The numbers only really make sense when you've got some context for them. And, if you have the context... why do you need the numbers?