Spam of the Future

In A Plan for Spam, Paul Graham predicts that the spam of the future will be very short and contain only a URL, because that's all that will be able to bypass content-based spam filters. He writes:
Assuming they could solve the problem of the headers, the spam of the future will probably look something like this:
Hey there. Thought you should check out the following:
because that is about as much sales pitch as content-based filtering will leave the spammer room to make.

I recently recieved a spam email which shows that Graham may be right:

Get access to the largest free adult site on the net.

My friends, the spam of the future.