As the author of the WWW FAQ, I regularly answer questions about the workings of the Web. If a question is frequently asked, I simply add an article to the FAQ. But sometimes a question is more detailed, more in-depth— not really a FAQ, but still of interest to others. You'll find those questions, with my answers, here in Innards along with commentary on other web-technology-related topics.

Q. "I set up a website with a company and they put it on Google for me. It runs out on the 18th of August and I cannot get hold of the company that I paid. How do I make sure that my website stays on google and does not expire. I am getting a bit panicky. Many thanks."

A. You do not have to pay anyone in order for your website to be indexed by Google. You can promote your website quite effectively for free, including adding it to Google. And no one, ever, is expected to pay Google simply to be included in their page index. See how do I promote my website?

Google is in the advertising business, but their advertising business only works because users trust them to display the most relevant search results. If that were to change, their business would dry up as quickly as it grew. This is why Google never sells "organic" search results (they do sell ads on results pages, but you can always tell the difference).

This does not mean that SEO (Search Engine Optimization) companies and techniques are always worthless. There are many things you can do to make your site more Google-friendly, and "white hat" SEOs will do these things for you. "Black hat" SEOs may also pay other sites, or create bogus sites, purely for the purpose of linking to your site. Those techniques usually result in a "Google penalty" in the long run, which can injure the search result rank of your site severely at least until you repent, stop the offending behavior and request a reevaluation of your site.

If your SEO company says your site is about to "expire from Google," what they probably mean is that they are going to stop promoting your site with paid links on other sites. That's black hat behavior, and you want no part of it anyway.

It's true that your site might experience a temporary dip in search result rank when such tactics stop. But in the long run it will rank better without them. The right way to promote your site is to design it in a search-engine-friendly way and encourage natural links from other sites that actually make sense to both webmasters as well as the actual person reading the site.

For more information, see Google's official SEO guidelines.

P.S. Given the tone of your question I do wonder if perhaps you are actually referring to your domain name registration (which has nothing to do with Google). An expired domain name is a more serious situation. Try a Whois search to figure out whether the domain is registered in your name, at least as the administrative contact. If so you may be able to renew it by contacting the registrar directly. If not, it may require the intervention of an attorney to prove the name is yours, which you probably don't have time for between now and the 18th. Track down those webmasters of yours. And in the future, always register your own domains via a registrar like GoDaddy and just point www.mysite.com to the IP address your webmaster specifies via the DNS control panel of the registrar's site. This gives you legal and practical control over the renewal of your domain and avoids problems with the occasional dishonest webmaster.