[digitalpoint]

I'm the one that did it in the example shown... I didn't use the $GLOBALS array, instead I did it like so:

<if condition="$post[postcount] % 10 == 1">

That lets you put it after whatever post you want, for example it could be == 4 if you want it to be after the 4th post. You could get a little trickier and take into account if users choose to display something other than 10 posts per page, but it was a 30 second job, and I was feeling lazy.