http://www.copyblogger.com/high-converting-checkouts/
- High-converting checkouts make prices more palatable.
- prices when they are listed without dollar signs
- decreasing the size of the type in which you present a price can tweak the impression of the price amount — as if a price that looks small is small, and a price that looks big is big.
- High-converting checkouts include free shipping (not just % off)
- "we’ll pay your shipping."
- High-converting checkouts make account creation feel less painful.
- “Continue” button brought in 45 percent more sales than a “Register” button.
- Modifying the language on the button to remove a friction-y sense of doing work