Edit: looks like the million dollar homepage is probably a bit more complicated than 2d knapsack, somewhat like tetris.

Another edit: looks like the only non-rectangular space sold on the million dollar homepage was the last space (as specified in the top linked article). So perhaps 2d knapsack is appropriate. It's late here.

I actually have seen the server that it was on. The hosting company provided free hosting to it for several years (at least 8 IIRC). I think that at some point the server died and Alex Tew decided to move elsewhere.

At one point, he had the million dollar pixel lotto which was the same idea except at two dollars per pixel and one person who clicked on one of the pixels would get half the money that came in.

The canvas was partitoned into blocks of 10x10 pixels that was white until sold. You would make a payment for X number of blocks through 2Checkout or PayPal. After transferring the money, you would send an e-mail to Alex Tew with the image, coordinates of wanted blocks, URL and TITLE/ALT text. He would then confirm the payment and upload your banner within 48 hours.

So the entire operation was manual with orders placed by e-mail.