Plurk lately allows their users to add custom emoticons as long as it doesn't exceed their maximum dimensions which is quite small. This, for some people are good news because they don't have to search for Karma (that's their scoring points) in order to get more emoticons. In the other hand, it makes an old users (like i do) are getting uninterested anymore with Plurk, since we got our emoticons by raising our Karma and we maintained it so hard.
Karma's increment decreases over time and to reach 100 from 95 took about 6 months itself (i counted it based on the average of 0.01 increment every four hours). It was really so painful to get Karma 100. Even after we reached 100, we still have to plurk regularly or it will drop quite big.
Right now, Plurk has unlimited Karma points and i had frozen my Karma point at 100.00 so that i don't have to worry about dropping my Karma point again.