No matter how many times I do them, I am always amazed at how much of a difference split testing makes.

I had a difference of opinion with a client recently about how a landing page for a fairly large budget campaign should be constructed. We went with a compromise solution, but I still wasn’t happy. I offered to do a test on the compromise version versus my ideal version. To his credit, he willingly agreed. The test isn’t quite finished yet, but so far it’s showing a 113% performance improvement - more than double!
If you aren’t split testing, why not? Of course, you can let me know if you want help with it.

Edit: test is now complete, at 158% improvement! Wow.