netmeg - 1:55 pm on Jul 16, 2013 (gmt 0)
The first thing you need to do is learn how to use channels.
Then make different ads with different channels for each of your placements (takes a little longer, but worth it) The code will be pretty much the same except for the channel. And name the channels for whatever you want to track - Top / Bottom Left / Bottom Right, or whatever.
Then you can place the code and test how each placement *actually* performs, instead of guessing.
You can have up to five channels per ad (at least you used to, I dunno if they changed that) and I use it to test sizes, colors, placements, pages, etc.
Very useful. You want *real* number whenever possible, not estimats.