I am a big fan of vertical Internet business models. One of the best I have come across is Artnet.

Artnet is the gold standard for dealers and buyers of fine art - particularly paintings and photographs. I have spent hours on this site and have watched in amazement how it has developed and rolled out service after service. It has terrific databases of auction records, art galleries and artists. It has free access areas, but it also has extraordinary subscription services that any serious art buyer and dealer must subscribe to.

I am amazed that some large media company has not jumped at buying Artnet. In the meantime take a look at an amazing example of a powerful Internet business model.