rvkumarweb - 12:04 pm on Jul 26, 2013 (gmt 0)
If the user will delete or expired ads automatically its an 404 page not found. Better way is to create a new custom 404 error page and re-direct too. Or use some techniques in case if you got any error page automatically re-directing to the home page URL or Sitemap.html page. (It will helps user engagement to stay on your website).
All the best :)