[jyotitis]

The whole Search Engine Optimization process can be divided among three major parts i.e. Crawlabilty, Content and Links. These three things are pillars of Search Engine Optimization and so to your site’s success path.

It’s obvious that if a spider can’t access your content then your content will not get indexed and so will never be found on search engines. That’s why crawlability is the basic and most important component of SEO and we will highlight these crawlabilty issues.

1) Screwing up Robots.txt file.
2) Too many variables or parameters in your URLs
3) Session ID’s in your URL’s
4) Your site suffers from code bloat
5) Your navigation and internal linking

Here I have summarized the important areas only, Read this in detail in a post at my SEO Blog , where I have explained how one can diagnose the SEO mistakes and how to rectify those.

Read the complete post here: 5 Common SEO Mistakes that can kill your SEO process

Please share if more mistakes you came across which can affect the SEO process drastically.

[sdolinsky]

Flash
JS Navigation
Frames
Key word stuffing
redirects


Just to name a few specific ones.

[HarveyJ]

Actually, as of last week, Flash is now indexable.
There was a big announcement that Google, Yahho & Adobe had been working on it.

[sdolinsky]

I just posted the news flash. I heard that they were GOING to start indexing flash soon. I'm not 100% sure what's going to happen. But i'm sure lots of sites will have their share of shifting PR's now.