I have a free classifieds websites, with categories/ads. Each ad is active for 30 days and then is marked as expired. How should I handle this better from SEO point of view?
1. Display the ad and put a message that this ad is expired? 2. Make a 301 redirect to category the ad belongs to 3. Make a 301 redirect to index page? 4. Other ideas?
At below-mass-scales, I would encourage you to keep the page content roughly similar to what it is, mark expired pages as expired, and maybe put a modal window with "This ad is expired. See related ads or post your own ad." or something on top of the old content, with an option for people to close that and see the archived content.
At mass scales (more than "thousands" of pages), I'd suggest either a) doing the above but also no-indexing those pages or b) 301 them to the category page. The rationale for this is that you don't want to get hit by Panda for having lots and lots of not-so-much-value pages.