Will,
You may be interested in a free advertising to help promote WO. I have started a site called ADEXlive. With running so many websites, I needed a method of promotion that didn't cost anything, so I came up with scheme having seen it successfully used elsewhere.
As the number of sites participating grows, so does the exposure of the site you are advertising. It works in the form of credits, for every 2 ads you show, you get 1 credit for your site ad. You end up with a "rotating banner ad" on your site.
For those without a website, who simply want to advertise a service/product or shop, you can "purchase" credits via paypal.
If you fancy giving it a try or for further information, take a look at
ADEXlive Banner Exchange