Here are some favorite Usability Quotes..

"Never lose sight of why software is being developed: to satisfy real needs, to solve real problems. The only way to solve real needs is to communicate with those who have the needs. The customer or users is the most important person involved with your project.

If you are a commercial developer, talk often with the clients. Keep them involved. Sure, it’s easier to develop software in a vacuum, but will the customer like the result?"

Alan M. Davis, 201 principles of software development

"Think of your product as a person. What type of person do you want it to be? Polite? Stern? Forgiving? Strict? Funny? Deadpan? Serious? Loose? Do you want to come off as paranoid or trusting? As a know-it-all? Or modest and likable?

Once you decide, always keep those personality traits in mind as the product is built. Use them to guide the copywriting, the interface, and the feature set. Whenever you make a change, ask yourself if that change fits your app's personality.

Your product has a voice — and it's talking to your customers 24 hours a day."

Getting real, a book by 37signals https://gettingreal.37signals.com/

"There are two versions of what happens online. There's the engineer's version, which is that smart people, with plenty of time, who know precisely what they want from their online surfing, are able to make a considered decision with access to all the data.

Then, there's the marketer's version. This says that people are busy, ill informed, impatient, not very thoughtful, and eager to click on something right now. […]

The second version is the one that's backed up with all the data and all the successful results. Because it's the right version. The first version is what leads most web-based companies to failure."

Set Godin, The big red fez http://books.google.com/books?id=ZKIOf9NvUnMC

"Now that Basecamp is 2.5 years old [as of 2006], we’ve been getting some heat from a few folks who’ve been with us since the beginning. They are saying they are starting to grow out of the app. Their businesses are becoming more complex and their requirements are changing. They want us to change Basecamp to mirror their new-found complexity and requirements.

We’re saying no. And here’s why: We’d rather our customers grow out of our products eventually than never be able to grow into them in the first place. […]

Remember, unless you’re Microsoft there are always more people that aren’t using your product than people that are. Make sure you make it easy for new people to get in. That’s where your real continued growth potential is."

Jason Fried, 37signals blog http://37signals.com/svn/archives2/growing_in_vs_growing_out.php