I recently read this How do I define the 'first' ad unit when using multiple ad units? The multiple ad units system serves ads to each ad unit in order of their appearance in your HTML code. In most cases, this will be the same order as the ad units appear on your page. However, if your code uses DIV tags or other positioning techniques, it's possible that our system will recognize an ad unit as the first ad unit, even if it appears to the end user at the very bottom of the page. Because our system may not always fill all of your ad units on any one page, it's important that you ensure that your 'main' ad unit appears first in the HTML code. at http://www.google.com/support/adsense/bin/answer.py?answer=10542 So my question is that the first ads in my HTML are link units, does anyone know if this statement above applies to link units as well? I get a lower CTR for my link units and I do not want the highest paying ads to go there because of this, if it applies to link units as well.
I _think_ google striclty distinguishes between "ad units" and "link units". The above text only seems to target ad units, not link units. but if you are unsure and you have unfilled units sometimes, why not put up a quick test page and try it yourself?