I am interested in SEO, but I still am skeptic of the lucrative nature of it. Why is it that I have never encountered a site protected with a content locker (survey-based) myself if it is one of the best methods of CPA available for content? I mean, sure, there seems to be lots of people out there willing to purchase BLOG or other such articles on the cheap for this purpose. But with all that you have to invest in SEO, it doesn't seem like returns are that great if you aren't following a successful formula down to a 'T'. Any thoughts? Please provide some sites protected with survey-based content lockers.