I’ve seen today that someone asked in SitePoint forums how to regain its web site rank within the search engines. The web site lost it after the a redesign. This happens very often and the reason is that web site designers make some mistakes in the code of web pages. Sometimes it may happen if anyone tries to use methods that are defined as a cheating or spamming ones from the search engines.
There are a few things that anyone should take into consideration when redesigns a web site.
Many say they are not important, but this is not true. Google and other search engines use them to compare what does a particular web site claim to be and what is the reality. So if the search engines like your Meta tags and the content of your web site, you do not need to change it. You can improve the designand to make it fancy, but to keep the content.
The other very important thing is to avoid saying things which are far from true in your Meta tags. Do not say “The Best Web Hosting Services” or “Best Rates for Domestic and International phone calls” if those are only a false claims. Users have to find the things you say on your web site.
I know a few examples of web hosting companies that received high rank on “best web hosting” and all of them are untrue. They got great position in the search results but I’m sure they will disappear very soon from the Top 100 results on realted search terms. It is not what it is! So It will not be on top for a long time.
Web Site Content
My advice here is to be descriptive. When anyone redesigns a web site, that means to think of how to improve a section and how to make anything more clear and more helpful to users. It is not just about the good looking web site. It is about the functionality. So do not make big changes if you don’t need them.
It is a good idea to promote those products, services or those content pages that users like most. Put them in your home page! This will make the Search engines to know that your web presentation is made to be used every day from many people.
Content Management Systems and Web Site Software
I can suggest you to discuss any migration from one third party CMS with another with a SEO consultant. Different CMS has different features and when you switch from one to another, you may change the way Search Engines see your web site.
The last I would like to say is to chase organic growth. Taht means to try to bring real people to your web site. Not to use linking method to boost web site PR. So do not try tricks and spend money to bring more quality and more visitors who will like what are you doing.