What reasons exist to use noindex / robots.txt?

[digitalstream]

Hi everyone. I realise this may appear to be a bit of an obtuse question, but that's only because it is an obtuse question. What I'm after is a cataloguing of opinion - what reasons have SEOs had to implement noindex or add pages to their robots.txt on the sites they manage?

[KeriMorgret]

Many reasons. You don't want the admin pages of your site indexed, for example. You may not want all of the search queries that people perform on your site search to be indexed. You don't want or need your cart checkout being indexed for an ecommerce site. You don't want a print version and a web version of the same document indexed, so you exclude the print version from being indexed. Your site is in development, and you don't want it being indexed before it is ready.

For robots.txt in particular, some search engines now respect wildcards and you can exclude some session IDs via robots.txt. OSCommerce is real bad about creating session IDs and getting those indexed, then you have tons of different URLs indexed for the same page.

http://www.cogentos.com/bloggers-guide-to-using-robotstxt-and-robots-meta-tags-to-optimise-indexing/ is a post that explains some of the reasons to use robots and no-index on a Wordpress site.

[Volusion.com]

There are a couple that come to my mind when i used them working for an agency. I remember one client had some temporary pages that didn't want to get indexed, explaining certain problem with a product at that time. We wanted the page to be live, but didn't want the problems that the product was having to show up in the search engines since it was just temporary.

Also, pages that are targeting same keywords that you dont want to erase or redirect and instead want to keep them live but at the same time you dont want to compete with the other main page. You just block it to the search engines.

Hope this helps

[digitalstream]

I really should have worded my question better. I'll try again.

**What reasons do people have for not wanting their pages show on search results? **

I've got a few reasons of my own, but I'm interested in seeing if there's any I hadn't thought of.

[Volusion.com]

For pages you don't want them to show up on search results. =P