
Many programs have the same kind of functionality, but they often differ greatly in terms of usability. The difference between just being able to do something and being able in a usable way is very important. A usable product is faster to use, gives you a higher user satisfaction and helps you keep focus.
A very real example of the difference, are the "reminder" functionality from Microsoft Outlook and Lotus Notes. Both programs allow you to create a task or an appointment and add a reminder to it. These reminders will then be displayed at a specific time using a dialog.
Lotus Notes 6.5
Microsoft Outlook 2003 See the difference? Both programs are equally capable of handling and displaying reminders. But, there is a huge difference in usability. Outlook provides the information needed (and then some) so that you can get back to your work as quickly as possible.
Lotus Notes completely fails to be usable, by displaying a generic dialog - asking a non-informative question - "You missed one alarm. Do you wish to display it now?". How do I know? How can I answer that question without knowing what the alarm is about? If it is about an important meeting with my boss in 15 minutes, then I would surely want to see it. If it is that I am meeting some friends tomorrow evening - it can wait. But I do not know any of this!
This is usability 101. Never ask a question that people cannot answer.
Secondly: Lotus Notes requires multiple steps in order to do what Outlook finishes in one - thus seriously damaging a person's efficiency. With Outlook it takes about 2-4 seconds to get the information and to take the appropriate action. With Lotus Notes it takes well over 15 seconds (based on GOMS).
And, the default action in Outlook will close the dialog, so if you are busy with something you can just hit [SPACE] or [ENTER] and the dialog will go away. With Lotus Notes, the default action will... well, not remove the dialog.
This is just one of many examples. It is not enough to just make functionality, if people are going to use the program it has to be usable as well.
Microsoft knows this, Apple knows it even more. Just look at Apple iCal (their calendar application), where the users goal and tasks have defined how the program works - not the other way around.
Full access for... $9 per month
Full access for... $99 per year
Join 'The Weekly Update' to get an email every Friday afternoon with the latest from Baekdal + noteworthy articles from around the web.

What the shift in media is really all about.
14 chapters
220 pages
31,000+ words
Free for subscribers
$8.79 on Amazon

It is not about creating a shop in a tab. It is about turning communication into sale.
29 chapters
156 pages
23,000+ words
Free for subscribers
$7.58 on Amazon

26
PAGES
BUY
NOW
...or get full access to everything + the books
FREE FOR SUBSCRIBERS

21
PAGES
BUY
NOW
...or get full access to everything + the books
FREE FOR SUBSCRIBERS

20
PAGES
BUY
NOW
...or get full access to everything + the books
FREE FOR SUBSCRIBERS

17
PAGES
BUY
NOW
...or get full access to everything + the books
FREE FOR SUBSCRIBERS

25
PAGES
BUY
NOW
...or get full access to everything + the books
FREE FOR SUBSCRIBERS

17
PAGES
BUY
NOW
...or get full access to everything + the books
FREE FOR SUBSCRIBERS

17
PAGES
BUY
NOW
...or get full access to everything + the books
FREE FOR SUBSCRIBERS

17
PAGES
BUY
NOW
...or get full access to everything + the books
FREE FOR SUBSCRIBERS

12
PAGES
BUY
NOW
...or get full access to everything + the books
FREE FOR SUBSCRIBERS

18
PAGES
BUY
NOW
...or get full access to everything + the books
FREE FOR SUBSCRIBERS

29
PAGES
BUY
NOW
...or get full access to everything + the books
FREE FOR SUBSCRIBERS

17
PAGES
BUY
NOW
...or get full access to everything + the books
FREE FOR SUBSCRIBERS

29
PAGES
BUY
NOW
...or get full access to everything + the books
FREE FOR SUBSCRIBERS

30
PAGES
BUY
NOW
...or get full access to everything + the books
FREE FOR SUBSCRIBERS

23
PAGES
BUY
NOW
...or get full access to everything + the books
FREE FOR SUBSCRIBERS

20
PAGES
BUY
NOW
...or get full access to everything + the books
FREE FOR SUBSCRIBERS

27
PAGES
BUY
NOW
...or get full access to everything + the books
FREE FOR SUBSCRIBERS

45
PAGES
BUY
NOW
...or get full access to everything + the books
FREE FOR SUBSCRIBERS

18
PAGES
BUY
NOW
...or get full access to everything + the books
FREE FOR SUBSCRIBERS

12
PAGES
BUY
NOW
...or get full access to everything + the books
FREE FOR SUBSCRIBERS

19
PAGES
BUY
NOW
...or get full access to everything + the books
FREE FOR SUBSCRIBERS

18
PAGES
BUY
NOW
...or get full access to everything + the books
FREE FOR SUBSCRIBERS

16
PAGES
BUY
NOW
...or get full access to everything + the books
FREE FOR SUBSCRIBERS

29
PAGES
BUY
NOW
...or get full access to everything + the books
FREE FOR SUBSCRIBERS

17
PAGES
BUY
NOW
...or get full access to everything + the books
FREE FOR SUBSCRIBERS

17
PAGES
BUY
NOW
...or get full access to everything + the books
FREE FOR SUBSCRIBERS

26
PAGES
BUY
NOW
...or get full access to everything + the books
FREE FOR SUBSCRIBERS

27
PAGES
BUY
NOW
...or get full access to everything + the books
FREE FOR SUBSCRIBERS

30
PAGES
BUY
NOW
...or get full access to everything + the books
FREE FOR SUBSCRIBERS

11
PAGES
BUY
NOW
...or get full access to everything + the books
FREE FOR SUBSCRIBERS