I have developed several versions of a Web Directory format.

The shopsandstores format allows the user to mouseover an image to view that business' profile or advertisement. The impulsive format allows the user to view the advertisers products without going to its actual site. The "iframe" technique shows a picture of the products or profile. I had an original version, as shown in the image in the index page, but it was totally impractical. The original theory was to have the content in the middle and advertisements on each side (you can view the original at http://www.oocities.org/geo_marksway/marksway.htm; mouseover the space ship at the right of the opening page, press the enter key, then click the ship image to enter the page).