Flash sites look impressive because of pretty and neat vector graphics, grandiose animations and cool sound effects. But in terms of benefits, building Flash-powered websites are overwhelmed by the disadvantages. When it comes to storing content and site navigation, Flash won't impress you that much.

Limitations to Those Who Do not have Flash Support

For websites such as small hotels or restaurants in a tourist area where people might just happen to possibly use their mobile phones to visit your site, not using Flash is very practical and highly recommended. I'm not saying to never use flash, but for certain websites, especially anything involved in the multimedia industry, Flash is almost a necessity nowadays.

Longer Loading Period

Flash files, especially those using sound effects, embedded movies or bitmap images are big in size and can take a while to load. Hence, if it takes too long to open your page, visitors will no longer wait and transfer to the site who's loading faster. Also, analog users will definitely have a problem in loading of Flash webpages and will likely lose interest and discontinue entering the Flash site. But for hi-speed DSL users, Flash will have no loading problem.

So, for maximum marketability, designing a pure HTML designed webpage (which is dial-up friendly) rather than a pure Flash website (which is DSL friendly) is the best option, since 80% of most internet users are still analog users.

Flash May Sometimes Ignore User Needs

While it's the basic rule of marketing to reiterate on the users' needs, Flash websites disregard them. For example, the sound effects can be inappropriate when you are browsing the web from a cubicle in a quiet office or annoying in the late hours at home.

Back Button is Disabled

"The Back Button is the second most important navigation element after hyperlinks" says Jacob Nielsen, the famous expert of web usability. In most cases, PPC marketing or promotion because Google AdWords would disapprove your pages.

Problems with Modification & Editing

Some developers code their projects in such a way that only them can modify or edit your Flash site. So you will have to hire them again everytime you will need to put some modifications to your site. The problem here is that web developers can take advantage of their secret code, charge you for additional expense when in truth, is caused only by their incompetence.

SEO Google Unfriendly

The word that confuses people is "indexing". In the SEO World, indexing content is the ability to read and archive content. Google is able to read text content in flash files if they have been correctly generated. When Google has finished reading the text content of the flash animation, it saves it in its database with all the other information about the page like the URL, title, incoming and outgoing links and 100 other factors. Now Google knows that page and has lots of information about it but for the page to show up in SERPs, Google needs to "rank" it amongst other pages.

Flash content does not rank as well as HTML content. The main problem search engines have with flash content is determining how will its contents appear in a browser. With flash, it's more difficult for search engines to detect it because the content may be hidden for a good reason, like being part of the second "page" of a single flash file, or it may just be spam.

Google will always prefer HTML websites because they know what you do with your HTML content and trust it more than flash content. Google also recognizes that people tend to link to HTML content because they can get a direct URL to the page they want, therefore passing link juice that Google loves. Most of the time, you can't get a direct link to the content you're interested in with a flash website and don't link to it.

Flash Movies Easily Become Obsolete

Thomas Fuchs says, that whether we like it or not, Flash is a technology that had its uses but is very quickly become obsolete." He noted that Flash video support only appeared in 2002.

Daniel Eran Dilger posted a comment by Morgan Adams (a developer who knows a lot about building apps in Flash), suggesting that the real problem with Flash is that it doesn't work - and can't easily be made to work - with the iPad (or for that matter the iPhone) because of the "hover and mouseover" problem

While Flash might not be the best choice for your business site, it's nonetheless the best tool we have for building graphics-intensive dynamic apps like banners, online games and videos. The website can be a fine piece of art, or it can be informational. Though usually not both at the same time, we must recognize that HTML is for content and Flash is for decoration and creative enhancement

Whether to use or not to use Flash in your site, my opinion is that you use not what you like most, but what is best for your company. For most companies, that would be to have a site built without Flash, but if it is a necessity for your business, then use it.