Website architecture plays an important role in SEO. Actually SEO should start even before you host your website. The website should be designed in both user perspective and search engine perspective.
Everyone does SEO. Why everyone? It is just because to increase traffic, traffic in turn gives ROI. So in order to improve your traffic and attract people , your website design plays the game. As face is the index of mind, your website creates a good impression on your company.
Let me give you a practical example, you are in search of online sports watch selling site. You just Google it and choose two of the top results. Both the sites which you choose sell sports watches online, but one site looks awkward with contrasting colors and Ad banners scattered here and there, while the other site is designed with interactive gallery for all category of watches with specifications, pricing etc. Just answer me. Which site will you choose to buy a watch? Its obvious, the second site which offers an interactive user experience.
So here are some guide lines for designing a search engine friendly website :
1) Lets start from the coding. Always use descriptive tags while designing your pages and use semantic code. This will help the search engines to understand your page and its theme.
2) As Google is still in the process of teaching its bots to read flash site and also one cannot expect every browser will have flash support. So its always better to have both flash-version and easy loading non-flash version of a website. So this will not frustrate users without flash support and reduce bounce rate.
3) Always use unique page title and your page title should reflect in your content, keyword and theme.
4) Avoid using images to replace text. If it is used always add “alt” attribute to an image.
5) It is recommended to test/check your website in all the different browsers available and load timing. Remember higher the load time, higher the bounce rate.
6) Install analytics tracking code to analyze the user behavior on your site and implement the needful on the basis of analytics reports. This will improve your site in a long run.
7) Finally, URL structure is also an important factor from SEO point of view. Having keywords in your URL is an added advantage. Avoid using underscores. It is better to use single hyphens.