I've been working pretty closely with Optimizely for the last year or so. I would go ahead and say its difficult/impossible to realize the advertised effect of their product. Can't speak to this one directly though.
I think leaving a store because you forgot your wallet is an edge case that only an extremely small percentage of bounces would relate to. I agree pop-ups are annoying, but I think its important to remember that HN users aren't necessarily the customers every business out there is targeting.
I was in your shoes not too long ago. Blogs and books are great, but in the end you should learn by doing.
You were probably looking for a more concrete source of some sort, but in my experience no books/blogs will teach you how to come up with original UX/UI design.
Its not the easiest task in the world by any means, but come up with a project (a website of some sort), and learn how to build it from the ground up.
Once you're done you'll have the skills you need to get a job in the field, and you'll be able to show employers your work to prove your qualified.
In due time web address conventions will move away from common TLDs. Why would you go to http://news.ycombinator.com when they can just go to http://news.ycombinator? Until then its not a bad thing to be creative with whats available.