The Mozilla Labs UX series is really interesting. Great use of community to get ideas for the next generation of the browser. I think they should use something similar to ideaExchange, but that is another issue.
One participant is Aza Raskin. He just posted an idea about tabs. However, I think the most interesting thing is a comment he made about Scaling. I noticed a similar thing when I was working at Intuit.
When you work on a business application, you can blur alot of lines and make alot of mistakes, yet still have a compelling and productive application. However, when you have a website or product that you use once per year, like upgrading Quicken, or doing your taxes with Turbotax, then you have to think about the tiniest details.
To Asa’s point, if you multiply 1 second of benefit times a million people you are talking about serious improvements. By contrast, 1 second of improvement in a business app used by 500 people is nearly meaningless. The more people that use your application the more the little details will matter.
Here is an example: Intuit had a checkout screen that put the details of your purchase in a block and then stacked different blocks for different purchases. This was “slightly” harder to read than the traditional “grid” view before checkout. This slight reading nuissance, resulting in losing 6 million dollars a year.
Lesson: When dealing with big numbers of users, focus on the smallest details. Leave nothing un-designed.
This is where Mozilla (Firefox) has a ton of opportunity to excel. They can look at super fine grained details and polish them to the ultimate smoothness. Each little detail will be multiplied millions of times over.