swa66 - 8:20 pm on Sep 18, 2013 (gmt 0)
You need to define "best" properly.
A higher CPC is what you seem to aim for as "better".
[Don't worry: I agree, that's what I like best as well: not to lose visitors over a penny or two)]
I'm pretty confident Google disagrees with that definition and they take the odds that an ad will be clicked into consideration as well (They aim for a predicted high RPM).