We have a website where users post classified ads on it. Each ad has an “expiry date”. After the date, we want the ad become abandoned and non-search-able by others. Also, after the expiry date, some users may post a new ad with 90% content exactly same as the old ad, and the expiry date is the only difference. They use this approach to “extend” the lifetime of an ad.

Yes, removing the page from search engine may lose traffic, but if not to do so,the website will end up with a lot of duplicated and outdated pages in the search engine’s view.

So what’s your advice to deal with this if there is no “unavailable_after”?

I work for a company where our clients import HTML into the system and send it out in bulk as emails (don’t worry, I’m not talking about spam, it’s all legit).

All of the emails are available as webpages until clients delete them (which they never do). With Unavailable_After, our clients can set an expiry on their newsletters so tons of several year old emails don’t show up on the internet. So it does have it’s uses!

Neuro, I agree that possibly newspaper publishers *are* Google’s ‘targeted audience’ WRT to unavailable_after. However, even if it is a CYA it deserves a comment when it is announced as a call for action, inviting you and me and everyone. An announcement like “dear newspapers, if you don’t want us caching your stuff and sending you free traffic after the initial coverage, just implement unavailable_after, a REP tag we’ve created for you guys.” would have prevented me from writing this piece. I admit that when the background is legal pressure, Google does not deserve bashing. I think my post doesn’t bash Google. If so, I apologize.

I bet this is so they can say to newspaper publishers (or courts) like the ones who took them to court.

“here is the mechanisiam for you protect your paid for archives so you can stuff your rinkiny dink protectionist court case up your ass”

And this is brilliant, “We don’t need no stinking metas” from “Another Brick in the Wall Part Web 2.0″