How does experts exchange get away with tricking google/users?

Question

I know from reading Coding Horror one of the reasons stackoverflow set up was

"Stackoverflow is sort of like the anti-experts-exchange (minus the nausea-inducing sleaze and quasi-legal search engine gaming)"

So, my question is about the quasi-legal gaming.

Example: http://www.experts-exchange.com/Web_Development/Web_Languages-Standards/CSS/Q_26543171.html

No answers displayed, have to sign up and/or pay to see them.

Then google search for CSS scroll range and select the first result http://www.google.co.uk/search?hl=en&source=hp&q=CSS+scroll+range

If you scroll right to the bottom of the screen, there are the answers!

So in essence, if you are coming from google you can see the answer, if you go directly to the experts exchange site and search for the answer you have to either be an active participant and earn the right to see the answer, or get it directly by paying.

How/why aren't they penalised for this?

Answer 1

This is actually a function built in by Google originally to help newspapers etc. It's called "first page free". News sites want their content to be indexed by Google so they can get search traffic, however, Google does not want to send users to a login page, so they compromised Google will index content that is normally blocked by a pay wall in exchange the publication is required to show the full content of that page to any visitor from Google. If you try navigating to another set of answers it will probably require to you login unless you go back to Google and search for it.

Answer 2

Google doesn't know that Experts Exchange is doing this because Experts Exchange only shows questions with answers to Google.

It used to be the case that Experts Exchange would hide the answers from the user but Google caught on to the tricks that Experts Exchange and other sites were using and EE had to change or risk showing up on fewer SERP pages.