There seem to be two approaches to invoking AddThis.
First approach is with buttons like the following:
<a class="addthis_button_facebook_like" fb:like:layout="button_count">
This seems to do a straight post on your FB timeline without any intermediate prompts or screens.
The second approach uses oexchange links such as:
<a href="http://api.addthis.com/oexchange/0.8/forward/facebook/offer?url=http://MYURLpubid=MYPUBID" rel="nofollow" target="_blank"><img src="required/btn_fb.png" width="100" height="24" border="0" />
This brings up the Facebook "Share this Link" screen and gives you an opportunity to type a message before sharing
a. What is oexchange? What is the difference between these approaches? Why use one vs. the other?
b. Is there a way for me to control whether there is an intermediate prompt/screen?
c. What are your thoughts on direct (without message/confirmation) vs. indirect with personal message?
d. Is there a way to pass in and prepopulate the message in the Share This Link window?