Points to be considered when designing a Flash based web site:
1. Purpose of the web site: If the primary purpose of the web site is to offer artistic or visual effects to the visitors (such as a business that is primarily a Design/Arts company, with visitors coming to the web site on some reference other than search engines) then Flash is recommended.
2. If you are developing a web site for getting more potential customers, then it is recommended to limit Flash only to certain portions of the web site or not to use at all.
3. Flash is not very search engine friendly. Therefore, a Flash-based web site may not rank well in the search engine results (Also called SERPs). It is important to know that search engines (as well as humans) like simple and quick to follow web pages, and not a complex and difficult to navigate web site.
4. Usually visitors are not interested in reading something passively. Keep in mind that most visitors spend less than 30 seconds on a web site. You need to offer the visitor what he/she is looking for in the shortest possible time (A good navigation system, and few number of clicks to reach the intended product or service).
5. A Flash movie becomes obsolete after a few months time. It is necessary to update a Flash web site regularly (This also true for non-Flash web sites also). It is more expensive and time consuming to update and maintain a Flash web site than a traditional web site ( In this context, a traditional web site is one that uses HTML with limited amount of script).
6. What about cgi or .php based web sites? These are server side scripting languages. The web page is rendered in html format to the browser. The web sites based on .cgi or .php are being indexed by most search engines, including Google. It is normally safe to use these technologies for web site design. However, some limitations apply.
The compelling reason to go for a web site developed without Flash is to get more visibility on the Web.
On the other side, if it is very important to impress the web site visitor with a visual presentation, use of Flash is inevitable.
Flash™ is a trade mark of Macromedia® Corp. and duly recognized