Why Flash isn't always good
Many people ask for flash based websites, believing them to be the best way of impressing visitors, having a professional and modern looking website and also giving visitors an interactive, and easy to use, browsing experience.
Whilst some of the above may be true, there are two areas in which Flash based websites lose out - accessibility and rankings.
The importance of search engine rankings should not be understated, after all, what use is a website if no one can find it.
This extract from an email from Google explains:
"While our spidering practices may change in the future, we find that Flash is not a very user-friendly experience in a lot of ways. It is wholly inaccessible to the sight-impaired, not renderable on many devices (such as phones, PDAs), and so on. In particular, we hugely frown upon navigation done exclusively in Flash."
I have seen many sites fall into the trap of using flash completely, some do have a HTML site too, most do not. Using flash for the site navigation not only means that Google may not like your website as much non-Flash sites, but it may also mean that Google is unable to find and index anything other than your homepage.
It also means that those using mobile phones, PDAs and screen readers will be unable to view your website, let alone navigate through it. This wasn't much of a concern in the past, but with most mobile phones been web enabled, you could be cutting out a large portion of visitors.
While things have improved regarding search engines, notably Google, since this email was sent, the fact remains that if two exact sites were made, one in flash, the other in CSS and HTML, the CSS and HTML site would be ranked higher.
This is an important point to consider, particularly for small and medium sized businesses. These businesses don't have the kind of income to spend on teams of SEO specialists to get the best rankings, unlike the big companies that they may be competing with.
SMBs are going to be paying quite a bit of money just to get decent rankings, so anything that could count against them should be avoided, and whilst non-Flash website may not look as attractive or as flashy; SMBs need to get the best possible rankings from their content.
The bigger picture
It is probably best to think of Flash like pictures, they may look great but you really wouldn't want a site made up entirely of pictures, unless you're comedian Jerry Sadowitz.
Apart from taking far longer than text to load, even if a picture contains text, it can't be read by the search engines. Jerry Sadowitz's site for instance has only these words associated with it: Jerry Sadowitz - Comedy, Magic and More, and only those words as they are the title to every page. The search engines don't see pictures, they only see text, so an all picture site such as that of Jerry Sadowitz is virtually blank.
Pictures should be used to complement the site content (text), not replace it. The same goes for Flash, it should have a place on a website but should be used sparingly and not as a replacement to a website.
It is possible to get a great looking site through CSS and HTML alone, and then of course any amount of pictures and Flash can be added to complement that.
Although it may change in the future, CSS and HTML is still the best way to tick all the relevant boxes when it comes to your website.