At Shop It To Me, we are always reading studies and articles on ways to help make shopping an easier and more fun experience .
I recently read a Ecommerce Usability study with some great insights on how to make checkout pages more efficient. If you haven’t read the summary of changes, I recommend it. A lot of the suggested changes are really small and at first counter-intuitive (which I always like).
Here’s one example on checkout expiration dates:
Many sites at checkout ask you to select the month of your credit card expiration from a list of names (i.e. They’ll be a list of months like “January”, “February”, “March”, etc… ) . At first, this just makes sense makes sense as people are more likely to think of “June” as a month than the number 6. Why confuse them?

The problem is that credit cards list the expiration as digits and not as a name (i.e. if your credit card expires June 2011, it will be listed on your card as 06/11 )
When a website asks you to select “June” as the month, they are actually forcing you to do the translation from 6 to “June” in your head. They are actually making you do extra work to check out. In the study, they found that just changing the expiration to two-digit numbers had a significant increase on completion rates.
You can see the remaining top 15 results from their report here, and the entire report can be purchased for I think about $80. Well with the investment if you are an ecommerce site with an existing checkout process.