Well, you COULD place the code in any of the custom insert fields or in a sidebar island, however you really want
offsite script code in your forum footer so the page doesn't hang for your users if there is a latency issue with the provider of the code (as if the code is lagged in displaying it could stop any content from loading after the external coding has been loaded in the user's browser).
This bit should be in your footer:
<script type="text/javascript" language="javascript" src="//c.amazon-adsystem.com/aax2/getads.js"></script>
This bit should be wherever you want the external bit to show (in this case, the ad):
<script type="text/javascript" language="javascript">
//<![CDATA[
aax_getad_mpb({
"slot_uuid":"9febd96b-2078-4146-b54a-be14fd7c03c4"
});
//]]>
</script>The offsite code only needs to be called
once whereas the other bit can be placed as many times as you want to use it (following their policy, mind you).
