As the previous comments, trends change, if you watch a TV show from 10 or 20 years ago, scenes last way way longer than the current ones (right now: 1-3 seconds between each cut!)
Even pages with long copy (Basecamp) have gone to a single shorter page.
A better alternative: Check sites with A/B tests and learn from them: http://whichtestwon.com/ http://unbounce.com/a-b-testing/shocking-results/
tl;dr: YMMV