Today, a lot of websites employ
flash animation products from companies like Adobe. Basically flash animation gives webmasters the ability to include small animated vectors into their web pages.
Appealing as these flash animations may be they do have a huge impact on how the website is seen by the search engines. Due to the limitations of search engine optimization for flash sites conversions and profitability of the website will be affected.
What Are Flash Animations?
When you create an animation, you get a file, named, for example, banner.fla. The ".fla" represents the Flash format extension. In order to display this file in a web page, you need to export it in Shockwave Format (extension .swf). It is this file, once exported, that you will be using for your web site.
Any text that you include in the animation probably won't be indexed by the search engine as they rarely give attention to these formats. In spite of this there are search engines (Google, dir.com etc) that are able to read the text in these animations. The result is that any site or webpage that is built entirely in Flash will be invisible to the search engines which index only text content in html format.
Why Do Some Webmasters Use Flash

Due to the limited content contained on sites built entirely in Flash search engines will have difficulty indexing them and will therefore avoid these sites. Additionally spiders are not abIe to read the content of a .swf file. Some webmasters use flash to build mini-sties for specific campaign sites.
Here are a couple of reasons people find Flash worth the effort.
It maximizes the animation's impact, which is appreciated in the Internet interactive and visual environment.
Flash combines well with other technologies like php, mysql, xml, video, sound etc. This makes it possible to include flash in a completely dynamic website.
Pros
It allows the designer to put more content in a small-sized space without damaging the layout.
Flash makes it easier to include slide shows and movies into a website.
Flash is ideal for creating banners, ads and flash videos.
It's a good instrument for creating great visual impact and drawing attention to specific points of interest on a web site.
Cons
Flash requires quite a lot of bandwidth and take a long time to load.
Most search engines don't like and don't index Flash.
You could be at the mercy of the Flash developers - if you use 3rd party Flash developers, they might code the project so that you won't be able to make any changes and you will have to pay them for modifications
The "Back" button is usually disabled for flash websites and also Google's AdWords won't approve pages that have the Back button disabled. So, beware of this if you intend to promote your web site by using a PPC campaign.
Flash doesn't care about the visitors' needs - movies that seem endless- sounds that you cannot turn off they will drive your visitors away.
Splash Pages will reduce your visibility in the search engines especially if there is insufficient text on the site that can be used to identify the keywords associated with your products and services.
It is not an easy task to optimize flash for the unpredictable search engines. The amount of time and energy it takes for SEO for Flash websites is far greater than the efforts required for an HTML site.