Insiders know what it is, but it's a new term to many.
Here's what you do:
Put a picture on your website. Something novel but still recognizable.
Or something really useful.
Then, put lots of links to various websites within the image.
Or, if you want, make it something remarkably honest or confessional or provocative.
Or make it a top 10 or top 41 list.
Then, tell the people you're linking to about it.
They link back to you because it's funny or new or makes them seem smart or just feels sharable.
It gets ranked up high on Digg and the other social networking sites.
You get a TON of visits. Like 250,000 new people.
Sure, only a few will actually click around and interact with you, but still, it's neat to have it happen and it might very well have ancillary benefits in your search results.
But mostly, do it because you can.
The web has been doing this forever, and it's likely we still will. It's a fine hobby, but I sure wouldn't want to build a business around it.
Here's today's example.