Smallest Changes for Biggest Improvement to ROI?

Simple question, really.

What are the smallest changes you’ve made to your campaigns to produce the biggest return in profit?

Some of mine:

1. Switching from Player A to Player B, and vice versa.

If the Player A spot on TrafficJunky requires a bid of 0.50, and the Player B is 0.35, and the difference in performance is only tiny, why would you bid on the more expensive placement?

You can sometimes add 20% to your profits just by finding the right placement where value meets performance (usually by deducting competition).

2. Using a native, professional translator.

You don’t want to stop at hiring a professional transl ...