If you are running a few affiliate campaigns and need more landing pages, here is a simple idea. What I do is get a domain name that can be generic like shophere.com and then I build a landing page for one of my campaigns. Then I create another campaign different product and so on. Then I add my individual campaign to a ppc network like Google Adwords. On my web space I can have the following:

(this is an example www.shophere.com is not my site and I haven’t even checked what was there)

http://www.shophere.com/footmasager.html

http://www.shophere.com/ironmanposter.html

and so on.

This way I do not have to have a domain name for all my campaigns and can keep filling up this domain with new landing pages.

On the display URL of the ppc network you can put www.yourdomain.com most people will not remember or try to click to the main page. It is a good idea to have a link to all the offers on your domain on the main index page, just in case there is someone who tries to see what the main page looks like.