Personally, I dislike the feature, but it does work better on some sites than others. Pinterest and Twitter use the technique appropriately. Facebook on the other hand, does not. Why do I say that? Have you tried to access the links they place at the very bottom of the page? It's impossible when content is being continually added, pushing those links out of view time and time again.

I don't mind having content immediately available in one place, but make me click to show more, don't just automatically continue to dump content in as I near the bottom.

That being said, I have a hard time seeing it becoming widely accepted for blog use. There may be a handful of unique situations out there where it works well, but I don't foresee it becoming the standard (fingers crossed!).

Of course, it's all a ploy to keep you immersed in the content longer. You get sucked into reading/viewing content and before you know it, you've gone through the equivalent of 20 pages of content when you might not have normally clicked past page 1.