I think there are different types of medals for different occasions. I'm quite happy to give a Fun or a RP medal based on a single message or action; I reserve Trust medals for longer interactions.
Haha,
That is funny considering that trust medals seems to be the most prevalent. I've got 6 of those but no fun or rp medals and I'm not the only one... I hope :p
EDIT: Personally I give trust medels when I've got some sort of gut feeling. I hestitate to give it to players who hide their name/country etc.
