You can use price discrimination to extract maximum consumer surplus, but there are other ways too. ( MBA here :-))

I think these games are more targeting "addiction-forming" (which is MBA speak for what any sane person calls "drugs").

The same sort of thing happened so mid-90s pay-per-second or pay-for-items games on what we now call dumbphones (ie. java games). They were regulated, essentially demanding up-front information about what they charge and an option to disable it on the telco contract (effectively giving parents a way to disable it for kids, and everyone a way to disable it for themselves), and their market completely dried up. This happened after several high-profile court cases where the telco was preventing from charging large amounts to kids (think $30k-40k). You can't find them anymore at all.

And that's just fine by me.

As far as I'm aware those things are still going, the one I remember was Jamster (though they use different names in different countries, so it was originally Jamba):

http://en.wikipedia.org/wiki/Jamba!

And the last link on the page goes to:

http://www.jamsterscam.com/

Which is a site for people who have been fraudulently charged, with comments from within the last few months.