Extended The Invitation To Visit.
When working on the content of a site, gaining inbound links, searching for link partners, etc., you may have submitted a few pages to the major search engines and received a vague notice that your site has been added to a list of sites to potentially crawl and index. A few months will likely pass and at that point, it is usual that the average site's submitted pages will not be listed in the top 100 let alone top 1000 rankings. Should you resubmit? The answer to this question may lay in answering this: was the site's home page, or at least a few pages within the site even indexed?
Try searching with a few URLs as 'keywords'. This can be an important step since you may not find the URL under a specific keyword or phrase, but you will want to at least know if the engine is aware of the site. This can be a bit time consuming since you might need to check for URLs with and without the "www." in them.
Did An Engine Just Knock At The Door?
If you have website statistics, you can see whether a search engine robot has been visiting your site. Many search engines robots have obvious names like Google Bot, MSNbot, etc. or unique names like Slurp, rather than the simple IP address/browser name combinations that most of your human visitors will have. If you are taking part in a search engine's paid advertising program, this can mean that your site will be indexed not only by a normal search spider but could also be analyzed by an advertising program spider. While advertising and submission services will not typically cause your site to gain an extra rankings boost, it can mean that your site will be indexed faster than letting the spider naturally crawl your site and incidentally, may mean that your site information is updated more often than a non-advertiser.
I Can't Believe They Still Have THAT In The Index!
Some time has passed and you've likely had a few pages that have been indexed. From time to time, engines will return to your site to check for updates automatically. When others link to your site, the engines can also follow those links back to your site and re index your site as well. This is why larger, more popular sites like CNN.com, BBC.co.uk, etc. are often quite up to date in the engines. Yet when looking at listings from your own site, you may find information that is out of date or different from the content that is currently on the page.
If your indexed content is out of date, first check your website statistics. Has the engine been by in the past few months? If so, it may simply take a bit longer for the engine to update its database and spread the updates throughout its various data centers. If they have visited recently, I would not resubmit this even if the contents of the page had changed. The engine's robot should come back to visit the page in the future whether I resubmit or not. If the date is quite old, such as 3-6+ months out of date, you may wish to resubmit if the page has updated information. If the content on the page is the same as the cached copy, there is no reason to resubmit and resubmission at that point will not help to improve your rankings.
