Using the advert box is a great idea!

I've always used one of the template files for that, but I like your idea better.

If the link doesn't show up, did you put the URL and make a link into one of the templates where you want the link to appear (such as header.tpl, footer.tpl etc) ?

If yes, then, you might be seeing an hold page stored in your browser cache. Do a browser refresh. If not, then you need to manually create a link to the new page you created. That's how the links show up. You have to edit the template file where you want this link to appear.