Clickthrough Rate. Slightly inexact because some clicks “get lost” between the click and your server. Also be sure to ask if the CTR is unique, meaning that each individual user is only counted once no matter how many times they click on a link.

3 Quick And Easy Ways To Build A Profitable Opt-In List
You finally realize that you need a good opt-in list. After reading countless articles and sought expert advices and have read many success stories of people creating a small fortune with opt-in lists you finally decide to have one of your own.