The book was written by Tim Ash of SiteTuners.com, a web analytics and site optimization service who does landing page optimization among other things for his living.
It is a real-world and practical guide to landing page testing and optimization without any fluff. It is really for the folks who do the testing and the ones who have to sell it to their boss and need to know about the details of the process of landing page testing, what is involved, what are the risks and how it should be approached and why.
It is very useful and complimentary to the "Landing Page Handbook" by MarketingSherpa, the $500 "bible" for folks who do serious landing page optimization for their business.
They also overlap in a few areas. This means that it is also a good buy for people who are not doing enough business that involves using landing pages to justify and recoup the $500 investment in the MarketingSherpa book. It's not exactly an alternative, but it is a start that cost a lot less.
If you are doing serious business with landing pages, I recommend getting both books. The return (increase in conversion = increase in business and profits) you will get out from it will pay for the initial investment quickly and then over and over again for the time to come.