Improve conversion rates through messaging? Yes please!

I am working on a user interface redesign project, and two of the ways we are planning to measure the success of the project are conversion and retention (renewal) rates.  We want to see an improvement in both of these so we are making sure that we are improving the interface and the user experience on the site.  We completed usability testing and learned that our users are happy with the overall design, can complete basic tasks and understand the concept of the site

 

Since starting to work on this project, I’ve done some research to investigate the best practices to improve conversion and retention.  Below is a list of interesting facts I learned reading a trendslide post; the research was completed by CityCliq:

• A good button size is 225px by 45px
• Red buttons have a 21% higher conversion rate than a green button (but I like green!)
• Certain phrases should be left out (or rewritten) of the purchase process 
•  “create an account to purchase” 
•  “empty cart”
• “reset form” 
•  “your session has expired”

 There are many more interesting facts, these are just some of the highlights.  Over the next few weeks I’m going to really look at colors and success factors for conversion.  Any suggestions on where to find information?  What successes (or failures) have you had in this space?