I find the messaging system on ebid quite a challenge as do some buyers I have heard from. I have to write some lenghty replies to questions and in such a small box it is so time consuming and I have to scroll right back to the start of the message to check for any typos.
Personally I would like to be able to respond to questions through email and even better to be able to put an email addy on my listings for potential buyers to use. I am sure it would encourage more questions, and perhaps lead to more sales?