I was just thinking about the purpose of multi-page articles (or any long web content that can be split into multiple pages), and I've come to the conclusion that the only real reason sites do this is to increase their advertising revenue.
Sure, one could claim they are doing it to decrease the psychological impact of seeing a very long page (encoraging users to read the whole article in less daunting chunks). Or one could say that it's to get a better estimate of the number of people actually reading the article. Or as a paging technique so people can more easily take a break and resume reading where they left off.
However, I suspect the real reason is more driven by money, and since ad revenue is typically per-load, that is probably why they have found ways to cause users to load pages more than once.
Yet another reason to hate ads. From now on, all sites that have multi-page articles or slideshows that require full page postbacks can die in a vat of acid.