I tend not to pm since I'm intense in my expression and that has been a focus of misunderstanding some time ago. I wish I was down to earth when I speak too, you know lighten the mood up and stuff but I get carried away and get uber intense instead which. Although it was 99% fluff you can't help but feel alienated when I get started and whoa did I throw some whoppers. So I rather refrain from such activity. I get the impression I don't know how to lighten up, like I have something stuck up my behind on a good day waiting for the barracuda in tomato sauce.
Pm's can be a lot of fun when its not intense fluff, unless you like that sort of thing.
Its curious to note that the introversion aspect is responsible for not wanting to initiate to responses unless people are familiar. The irony being that people get familiar with responses. I have that same problem, friends tend to call me to go out way more then I indicate when I want to go out. I've never thought it can assume the same form online until now.