mmcfadden, you're correct on the column, but you didn't say why it's the most important. scottybuzz and FlexxAeon are correct, you do need to filter low traffic sponsors with skewed results out of that column, but $/unique is THE column there.
But the question remains... why is it the important column? The answer will explain why woj is wrong about looking at the bottom dollar. Sorry man.
FlexxAeon, I see you edited your post and added an explanation. You're close. What does looking at $/unique allow you to do (and specifically, allow you IGNORE)?