Let`s not even get into the infringement, but looking at the site, I don`t see any home page that tells me what you`re doing and why I should use your service instead of going directly to Craigslist. There is also no easy way to get back to the home page.
Infringement would be something to worry about. That said, interface could be easier to make sense of as others said. As far as usefulness, could you allow people to sign up and create a saved search and have your site email them when matches are found so they do not have to search daily if there is something they want. I always thought that would be a cool tool for CL that doesn`t exist.
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