Have you ever wanted to know what other sites share an IP number with your client? A search conducted using this format at MSN: ip: ###.###.###.###, will reveal all the sites in the MSN index hosted at that IP.
ISPs have a limited number of IP numbers and recycle them from customer to customer. Search engines keep lists of IP numbers that were used by “spammy” websites. While it is rare, some new sites are placed on IPs that have been previously burned.
One of the research steps we sometimes have to take is to call our client’s ISP to find out as much as we can about the history and sharing-status of our client’s IP number. The MSN IP-search function will be a great help for us, hopefully saving some research and telephone time.