It's been mentioned, but more/better ad copy on the index pages would be good.
On pages like this one
http://www.skippyandscooter.com/testing/kbp/kat.htm
I would throw some ad copy or a banner under the title graphic, rather than actually linking it... and with a nice obvious Enter link like that, you can get away with sliding it further down the page to make them scroll to get at the free content link.