I think I understand a little of what you mean.
I always try to answer people's e-mails right 
away if I can- as a collector/buyer I hate 
waiting, so I figure other people do too.
But sometimes I can't answer some questions- I e-
mail a lot at work because the connection is 
faster, but I don't have the cels at hand to 
answer things like sequence number.  I don't mind 
people chatting a bit about cels, if I have the 
time I really enjoy discussing them.
I think following up after a transaction is 
really good too, I usually try to e-mail people 
if I don't hear from them, "Hey, did you get the 
cel yet, do you like it?"  
Fortunately most people will e-mail me when they 
get a cel, and say thanks, and that makes me 
happy.
I don't always e-mail dealers to tell them I 
recieved cels- sometimes, but not always- I 
figure they probably get tons of e-mail anyway, 
but if I am totally ga-ga about a cel or it has 
taken a while to get it I generally send 
something.  ^_^