Sometimes the source of the problem is so glaringly simple that you would never consider it. This is the case of many webmasters frustrated with their sites not being indexed or ranked by search engines. While there are numerous more technical reasons search engines might refuse to index your page, a surprising amount of time the problem is caused by you telling the search engine not to index your site with a noindex tag.
This is frequently overlooked, but it can put a complete halt to your site’s rankings and visibility. Thankfully it is also very easy to fix. The biggest hassle is trying to actually find the redirect, as they can be hard to spot due to redirects. But, you can use a http header checker tool to verify before the site page redirects.
Don’t be embarrassed if this small mistake has been keeping you down. As Barry Schwartz mentions on SEO Roundtable, there have been large Fortune 500 companies with these same problems. John Mueller also recently ran into someone with a noindex on their homepage. He noticed a thread in the Google Webmaster Help forums where a site owner had been working to fix his problem all day with the help of the other forum members. John explained the problem wasn’t nearly as complex as everyone else had suggested. It was much more obvious:
It looks like a lot of your pages had a noindex robots meta tag on them for a while and dropped out because of that. In the meantime, that meta tag is gone, so if you can keep it out, you should be good to go :).
When you encounter a problem with your site ranking or being indexed, it is always best to start with the most obvious possible causes before going to the bigger and more difficult mistakes. While we all like to think we wouldn’t make such a simple mistake, we all also let the small things slip by.