SEO is not just about keyword density and link building; it also has a lot to do with design and back-end programming. If your website design is not spider-friendly, it won't get crawled and, naturally, you won't rank for your keywords.
The popularity of the search engines has made website design a continuously juggling act between keyword density and aesthetics and of ranking well with the search engines whilst holding visitors' attention. On some sites where a flash design is more appropriate, website owners strike a compromise by designing a pure HTML version of the Flash website.
The rule of thumb in designing, however, is to always keep your visitors in mind – the search engines come in only secondary. After all, if it is not SEO, there are other ways to promote your website – like email marketing campaign, viral marketing, and launching a Google Adwords campaign. You can also write blogs and PR articles that have active links to your website.
When designing your website, don't even think about going around search engines by using black hat techniques like cloaking a keyword spammed page with a very nice copy for website visitors to see. Using black hat methods is just good for the short-term, and you can actually get removed from Google's index of websites if you do. Besides, there are times when visitors can actually see the cloaked content (spam and more spam) - not a very pleasant experience at all for your visitors.
So it goes that the key to successful ranking is to be mindful of your designing and programming. In general, easy navigation and "crawl able" content or content that can be crawled by search engines are the keys to a successful SEO design.
Set-Up And Design
Search engine spiders cannot crawl websites with dynamic URLs. A dynamic URL has any one of these characters in them: ? & % + = $ cgi-bin .cgi
If your website has dynamic URLs, try submitting to the search engines the non-dynamic URLs that point directly to the dynamic page. If not, consider creating static pages on static URLs.
Search engine spiders do not do a very good job of indexing websites with frames, in fact, they're very bad at it. Redesign your website to a simple HTML if topping search engines is your priority.
The problematic thing about frames is that search engine spiders do not see
"crawlable" content when they search frames.
Flash elements themselves are not problematic. They only become problematic if they are not used properly (the SEO way).
Designing splash pages is one of the biggest SEO mistakes, precisely because splash pages aremade up almost entirely of flash. If you need to use flash, insert as much keyword-optimized text as you can and write a title and meta information in the source code.