The search engine optimization industry is a fascinating world. Here is my (ongoing) list of things you should avoid when building a website:
- keyword stuffing
- broken links
- badly configured robots.txt
- meta keywords
- duplicate content
- copied content
- no content
- no sitemap
- no 301 redirects
- slow page load
- Flash
- lots of javascript
- automated title tags
- no images
- stolen images
- …
Of course there are many more, some obvious and some not so obvious. Be careful out there! Sometimes it feels like the wild west.