How about scraping yearly listings? I do use it but I would never remove a quality listing as I would be removing content. I have to agree that some people may take it that way. Thanks Brian
Excellent tip! Providing them would be like "buying content on rent". Once some content is on your website, you want it to be on it. It might be good for huge directories who get a lot of submissions to keep maintaining the website. Some websites close down and then linking to 404 websites doesn't really increase the quality. Still keeping them permanent seems a better option to me.