The 10 most egregious UX offenses against users. Web design disasters and HTML horrors are legion, though many usability atrocities are less common than they used to be.
If you took a day and fixed any of these Top 10 Web Design Mistakes That Apply you would make 50% more this holiday season. These are "cost of poker" fixes that can easily remain for years and years. Every year one of these mistakes exists your website is 10% less effective.
When you make 2 or more of these mistakes you pay with an order of magnitude more pain for each added mistake so 2 mistakes doesn't cost you 20%. No 2 mistakes cost you 200% of what your website could be doing for you.
Fix all 10 of these basic problems and your site is on its way to its "mission critical" place in your company.