Let’s imagine you are starting a web site to promote an event, such as a Hallowe’en party or Christmas market. Perhaps your site is there to advertise a concert tour, and the last gig will be at the end of October. There’s no point in cluttering up everyone’s search results with your site after the tour or the party has taken place, is there?

Trouble is, after the party, people often forget about the ‘loose ends’, and loads of their old out-of-date web sites are left online forever.

If you know that your site is going to be needed only for a limited period, and you don’t want to have to remember to take the site down afterwards, you really should use this meta tag:

<meta name=”googlebot” content=”unavailable_after: 31-Jul-2008 12:00:00 GMT” />

Obviously, change the date and time to your own requirements.