Stupid ways to hinder market adoption

I admit it, I do read Guy Kawasaki's blog on a regular basis. Sometimes I find his posts to be slightly off topic (at least for me), but other times I find them to be incredibly insightful. His latest post, "The Top Ten Stupid Ways to Hinder Market Adoption", provides a pretty good summary on surefire ways to slow down / hinder / eliminate market adoption of your product (provided that it is a web based product, but I am sure you can extrapolate out some of these and apply them to your product if it is not). For the details, read the article, but here is the high level summary so you get the gist (reader's note: he actually lists 14 ways even though the article is titled 10...)

1. Enforced immediate registration
2. The long URL
3. Windows that don’t generate URLs
4. The unsearchable web site
5. Sites without Digg, del.icio.us, and Fark bookmarks
6. Limiting contact to email
7. Lack of feeds and email lists
8. Requirement to re-type email addresses
9. User names cannot contain the “@” character
10. Case sensitive user names and passwords
11. Friction-full commenting
12. Unreadable confirmation codes
13. Emails without signatures
14. Supporting only Windows Internet Explorer