Why my weblog is to trade???

I set up web stats now, then just out of curious clicked Referring Link.

I was astonished to see the site that displayed "my other weblog named Cryptonomicon is Available to Trade"

Why my weblog is to trade?

And then I took a look at the site named Blogshares.
It appears to be a game something like virtual stock market.

I'm amazed that there is a lot of site I don't know in the net.