Anyone wanting to cancel catalogs they receive in the mail (either in their name or someone else's). Also, companies that want to avoid sending catalogs to people who just throw them out.
Usefulness of Content
I have to say that it has been quite a while since I found a site I was happy to see that someone had made and hoped for its success. The site has environmental information on how canceling catalogs saves trees/landfill/etc. It has a simple to use interface for subscribing (you will receive an email with a link to confirm). Your account is tied to a mailing address and you can list any names that receive catalogs at the location. They handle contacting the company that the catalog is from asking them to remove the name/address that you listed. Their list of catalogs is amazingly complete. In a month of entering catalogs I have found only 2 out of 70 that I entered were not in their database.
The site is sponsored/run by several environmental organizations and has a way for catalog companies to get involved and has several major catalogs merchants signed up - the site allows merchants to login and get the cancelation requests rather than have to get hundreds of emails which by law they have process.
There is no advertising on the site.
Consistency of Design
Very simple site. Limited number of pages with a simple consistent navigation. Login/Logout at top right corner, menu on left, link for Merchants/blog/contact info at bottom. Simple easy on the eyes green/white colors (I'm guessing green for environment...)
Ease of Navigation
Very simple, easy to use. The actual catalog cancelation application allows you to search for a catalog by typing (it dynamically shortens the list of catalogs as you type) or by looking in an alphabetized catalog. You can also quickly see the list of catalogs you have declined sorted by name the catalog was sent to - each entry has links to modify your request, let them know that you are still getting it and a link to the catalog vendors website. When you actually enter the application to cancel a catalog you can enter a new name if the one that is on the catalog is not one that you have entered before. The list of names you have entered is available in a pull-down menu. While in the application you are in a new "window" in the forefront with the site behind it grayed out and inaccessible. Overall, a very nice job.