This is a pretty flexible technique, though, like so many others which attempt to resolve complex problems with just CSS, it too has its quirks and caveats.
You can have all sorts of content within these blocks. Like an image!
Or even a Google Maps iframe!
It's not a revolutionary technique, but the thinking behind it is pretty creative.
How about a YouTube video?
The only real downside with this approach is the awkward alignment of the blocks. They align like in a newspaper, according to columns, not rows.
As such, it's really only suited for layouts in which the order of the blocks is less important than the style of layout. Think Pinterest.
Fun fact, this technique dates back to May, 2011. Pre-Pinterest, that is.
However, Pinterest does not use this technique. What do you think, should I pitch it to them?