Web Design for ROI is an excellent book for reviewing all those website elements that help convince the user to click on the call to action button. As I read the book I’m creating my own checklist of website elements that should be considered for every website. Below is my list, I reccoment reading the book for better a more indepth understanding.
Web Design for ROI

Define the Big Picture
Are the following questions answered:
▪ Define the website owner’s objectives?
▪ Define the website audiences?
▪ Who is the competition?
▪ What are the expected traffic sources?

Measure Success, (know what’s working)
▪ Setup stats tool
▪ Define the call to action
▪ Connect call to action to stats tool

Landing Page Design Guidelines
(choose the guidelines that apply to your particular website)
▪ Establish credibility
▪ Use industry-aplpropriate design
▪ Display excellent references
⁃ awards
⁃ newspaper and magazine quotes
⁃ certifications
⁃ testimonials
▪ Minimal Navigation
▪ Make page appearance consistent with next landing page when using an affiliate link
▪ Make sure offer is consistent, match the wording
▪ Offer segmenting options for different products
▪ Eliminate nonessential graphics
▪ Accommodate different reading patterns (titles, paragraphs, bulleted lists)
▪ Place the call to action in each type of reading pattern
▪ Make buttons look like buttons
▪ Button text should be specific and motivating