I cannot see where that would add that much of an additional load on the server over just keeping track of the karma count. The karma reward is a one-time deal, and it should not be as easy as a "like" button. That seems to me to be a bigger load on the server.
But the "like" button is still better to me than no karma at all.
Keeping track of who "liked" who, when each "like" was given, which particular reply "triggered" the "like" and a comment for each "like", plus displaying a list of all "likes" in user's profile page is not as simple as keeping a "karma counter".
Implementing all this might not a big deal either, but given the number of users, messages and posts in this forum I guess even a small increase in php and sql load could add significantly to the overall server load.
If you did keep track of all that, it would be a bigger load. I can see that.
The MT forum doesn't store any of that, just the karma count. Just like here now. But before it will increment the karma count on a user, it sends a PM to the recipient from the sender with that info, but none stored permanently in the database, except in that one PM. You may delete that from your inbox if you like.
edit: The "Give karma" there is a two step process. You click the link in the topic, and you get another page with a form (message box) and a "Give karma" submit button.
@surferTim
I gave you a Karma and I think you deserve it. Whether is is to easy or not depends on how much value you think a karma is worth. I see it indeed as a "I like that post -and I can't remember you annoying me lately"
"I like" ] the 2 step process you mention. It strengthens the positive message and it allows the receiver to understand what (s)he did which was appreciated.
The current Karma implementation does not even allow the karma receiver to know which action triggered the sender.
Technically speaking I think any implementation of a 2 step process will have some load consequences.
For instance the extra mails being send (which do not get cleaned up).
But he; don't we all like increasing scores :D?
So I'll enjoy it as long as it lasts.
What's to stop me giving AWOL 100 karma by just clicking his Karma button 100 times? If I can, surely it is a useless measure, because it can be abused. If I can't, it must store somewhere that my user name (or my IP address) gave someone Karma. So, that's extra load. And extra load to check, for every poster, whether they can increase the Karma of every other poster.
And once I give Karma to one person, how long until I can give it again? An hour? A day? A second? More computations.
I just don't think it measures anything useful. Someone here may be an expert on something obscure (eg. UDP packets) and post occasionally, when they can say something useful. But when they post they give good advice. They might have low Karma. Others may post a lot but just ramble, but have a few friends that boost their Karma, like a mutual-admiration society.
For me the post count is a useful guide. Someone with lots of posts has, at least, hung around the forum long enough to hopefully know something about the Arduino, or at least where to find things out, or where another thread might be that would help someone.
For people with few posts, you can still respectfully read what they have to say, and if they seem to know what they are talking about, follow their advice.
About this Karma thing. About the only thing more useless then the karma count is the long posting threads it causes after it's activated, as this one it likely to become. Someone should find the long thread created the last time it was implemented here, that time with plus and minus karma counts shown. It was quite funny following that thread but had the equivalent value of a delay(max long integer) time sink. But thankfully someone killed it before the rollover happened.
Actually that might be the best solution for the Karma counter, just make it an unsigned byte that will roll over, so even a karma count of 0 won't mean anything significant. 8)