I have a website. Some time ago some pages begun to become supplemental, why would this happen? And what are the effects on SEO?
I had the same thing happen to a site last month. Took 3 weeks before they came out of Sup index after making some changes. There were no issues with meta tags. They were all unique. and content was unique on each page except for a couple paragraphs of text that were site wide in the footer. Also had site wide footer links to my entire network of sites. I removed that footer site wide stuff. But today i noticed that they are all back in Sup again. I'm sure this is a short term glitch. Back when they first went Sup there were 30 pages on the site that were cached by Google. Made those changes and added a few more pages. The other day I saw 34 pages in cache. Today when I saw them Sup again i see again only 30 pages. Looks like Goog has reverted to the older index for some reason. It's probably very temporary. I hope so at least.
To get rid of those supplemental result pages (actually to have all your pages into the main index), you should work on the following areas of your website: 1. Make sure you have good meta-tags on all your pages, meaning all pages should have distinct title, distinct descriptions (minor differences are good, but try to have them really different) and also, make sure that these meta's are close related to the content of your page. 2. Make sure you have search engine friendly URL's. 3. Make sure you have parts of the title into the URL. 4. Make sure each page from a website can be reached at a maximum 2-3 clicks distance from your index/main page 5. Make sure all your pages are inter-linked.. so every page has at least 5-10 other pages that link to it. 6. Make sure you have deep inbound links, which are links to pages other than the index/main page. 7. Make sure you don't have duplicate content, neither in your site or regarding other sites on the web. That's all I'm thinking of right now. Follow these guidelines, and you will see improvements in your indexing status. Best luck, Ciprian Sorlea.
The pages I am refering to are 'order pages' so apart from the different product information the pages are pretty similar. The meta tags and titles are also very different. Would a noindex/ no follow tag on these pages help prevent pages cause duplicate content penaltys? Would this be the quick fix?
Yes, re-look into your content, titles and META tags. Try to allocate unique description for each of your page.