2 CPM Questions: Ability to track click and Best CPM Size?

[weldonj]

Is there some dynamic phrase I can put in the URL text that will track which CPM site my click is coming through?

so for example: www.myurl.com/{site} and site is the site the CPM ad runs on. I know google has {keprhase} and {creative} which I can't find any documentation on so I was wondering if there was a site phrase as well.

This would be a very effective way for me to see which sites are good and which are crap. I don't want to have to look at the server logs or create a different URL for every CPM site.

And secondly, what banner sizes are the most prevalent for CPM image ads? And is it possible to see which of the sitse in a CPM campaign accept image ads? I've just been operating in the dark in the past.

Thanks

[eWhisper]

The dynamic insertion to show the referring site (only works for site target)for is:
{placement}

So, a fully formed URL with all the insertions would look like:
http://www.example.com?src=AdWords&medium=PPC&campaign=AdGroupName&Network={ifContent:Content}{ifSearch:Search}&kw={keyword}&ad={creative}&SiteTarget={placement}