I recently had the pleasure of a client at work that wanted pagination for his online newspaper-thing, and so I had the opportunity to think a bit about pagination on the web in general, and why it, in many cases, is a bad idea.
First, let me make a distiction:
Now, this is the good pagination. The kind of pagination (Ajax or not) that saves my browser from having to load all the 538 comments on an interesting piece of news on Digg. The kind that gives logical separation of a manual or a long book.
This difference here being that the pagination is either not of the main content or separation of a document you probably don't want to read in its entirety anyway. The only real exception to this is books presented on the web, which are (in my opinion) too big for the web. If I'm reading a book, I find that it's a completely different thing that reading the web. For books I prefer some kind of downloadable format that i can use with my e-book reader, Stanza.
Now, this is something else entirely. The splitting up of something that belongs together. I'm not completely sure why it is done, but I suppose the purpose is to show us more ads to drive up the revenue, but the fact is that many online publications today use this approach.
This annoys me greatly. When I'm reading an interesting article on something, I'm forced to break my flow and find the link and wait for the page to load. And often, I'm not even on the web when I read stuff. I have a strategy to go through my RSS feeds before going for a train ride or something else where I won't be online and open all the interesting stuff in tabs in Firefox so I can read it later.
Besides this costing me extra time, it also costs resources. Each pageload adds costs, both for me and for the content provider, so while it might look nice on your page impressions statistics, it probably won't bring you more revenue, only costs.
So in my opinion, any kind of article, opinion piece or whatever is atomic. Either I want to read it all, and then you might as well just give it to me immediately, or I don't want to read it at all. I mean, whoever reads only 1/3 of an article?
So please, if you have paginated content on your website, or are thinking about adding it, please consider this. Why do it? Besides showing more ads, I can't really think of a reason.
Although I wrote this the 14th, I didn't get around to post it until the 20th. In the meantime, I found that John Gruber apparently agrees.