" 'Instead of a 20 paragraph page, breaking it up into 3 or 4 pages that each address the subheadings of the topic will garner more traffic and more adsense revenue.'
BINGO! This is spot on. It's all about multiple traffic streams and leveraging content you're going to write anyway. Turn one long page into several pages, and focus like a laser beam on just one or two related keywords per page. Search engines love that, and it makes your AS ads very targeted.
Look at it this way: you want your visitors to get value out of what you write, and they will whether you give them one long page to read or several pages of shorter length. In fact, I've found (from reader feedback mostly) that visitors appreciate smaller chunks of content. So that, alone, is reason enough to make more pages of shorter length. But what really makes it a no-brainer is that instead of one page with the chance to rank highly at the search engines, you now have 3-4 (or more) pages that focus on only one or two keywords each instead of a bunch. The result will be (usually, but not always) new traffic streams from searchers looking for EACH of those keywords instead of just from the generic topic. In my experience, this is virtually always the better way to go for the long haul." Swebbie