MobileRead's Karma system
This is an expansion on the description of MobileRead web site.
 Overview and Formula
Each person to starts out with 1 point of influence (after they've posted at least once), then it follows a formula:
(# of days registered/30) + (# of posts/40) + (Giver's present karma/200)
and the result will be rounded down to the nearest integer
Remember, these are all based on the karma giver's current stats.
So, for example if a person who had been registered 300 days, had posted 2400 items, and had a present karma of 400 were to give someone else karma:
(300/30) + (2400/40) + (400/200)
10 + 60 + 2 = 72
So If this theoretical person were to tap someone who had, say 28 karma points already, the tapee's karma would increase to 100 points.
The biggest single factor is how many posts the karma giver has made, the more posts the faster the givable karma goes up.
There are some limitations on tapping:
- The only way for a person's karma to rise is for someone else to give them karma.
- Once person A gives karma to person B, person A cannot give karma to person B again until person A gives karma to at least two other people.
- The most persons that can be tapped in a given day (24 hour period) is 10.
- No single post can be tapped more than once by the same person.
- No one can give themselves karma.
 Extra Notes:
Your karma entries, including the tapped post and comments can be seen at the bottom of the user control panel.
vivaldirules described karma thus : "It's like kissing someone while wearing bright lipstick so that others can see how many times (and maybe where) the person has been kissed. And it doesn't come off no matter how hard they may scrub."