I just wanted to share for those who have not tried link units. We added them in to a few of our sites and picked up an extra 25% in click volume overnight - for us this translates into some pretty decent money. The price per click seems to be about the same as the ad blocks but it's very early days yet.
Thanks for the information. I've tested AdLinks on various sites and pages for years and it seems they either perform very well or not well at all, not much in between. But it's certainly worth testing because the pages where they perform well make it worthwhile.
In the past I've asked Adsense to generate a separate "heat map" for the link units. I think it might be different. (There's been no response). I have found link units can help monetize a web page's footer, obviously a place people might be exiting a website anyway.
Add placement heat map info. [google.com...] Google's code for the page has some problems! The heat map is only on the non-secure server. [google.com...]