Well, as most of you know I have a Christian t-shirt website called http://www.SimpleLetter.com that I've been running for a little over 1 1/2 years. Being a webmaster by day, I've got a bit of experience doing various web development tasks and creating web applications. I have two roommates who are tech-savvy designers and naturally we got together and started up a christian company.
In my spare time, I've spent a ton of effort into learning and applying great SEO techniques and making my website one of the first to show up for clothing, apparel, or t-shirt related searches on all the major search engines. Finally, all that hard work is starting to pay off.
Let me start with the present...
As of the end of Feb 2005, our website is now in the TOP 10 in Google for the search prase "t-shirts" and in the TOP 5 in Google for the phrases "christian t-shirts", "christian clothing", and "christian apparel". Our hits have probably increased by 10x-15x in the past 2 months as this has changed. We sell about 1-2 t-shirts a day which is a huge jump up from the past.
"t-shirts" is an incredibly complex and competitive keyword as the first page of results have sites with THOUSANDS of Google backlinks compared to my site's measly 116. (Of course, I have many many more backlinks than that, you can use the tool here to check out the vast discrepancies between search engines: http://www.justintubbs.com/backlinks )
Before this time (late 2004), we were selling about 15 t-shirts a month, or about one every two days. Our rankings for "t-shirts" were in the 50's in Google, and for "christian t-shirts" we were in the low 20's.
Back in early 2004, we had several months when we didn't even sell t-shirts at all, and our rankings were in the low 100's for "christian t-shirts" and low 200's for "t-shirts".
What's my key? How did our site survive the SuperBowl 2005 Update ( http://forums.seochat.com/t22926/s.html ) on Google? I have no clue. All I can say is that my focus has SOLELY been on internal links that are related to my theme. I don't focus on content, page copy, keyword density, or even on individual <meta> tags for each page. Just get lots and lots and lots and lots of incoming links to your website. That honestly, is the most important thing I can say from experience.