I posted this on Mozillazine. I thought I'd repost it here because I found it interesting:

Over the last few years, I've seen many people talk about how there isn't a good killer feature in Mozilla. Or in Opera. Or Linux. Or in any other product one might mention. Marc Andressen recently thought so too. Why? Because killer features don't exist. You can't create them.

One could say that tabbed browsing, or popup blocking or any of the Firebird extensions, or 'tools to organize and information-overflown workflow need' (this quote from the post I was repying to) are killer features. Are they? They could be. But they really aren't. Even though I use Mozilla because of them and wouldn't use a different browser.

You see, when a new kind of product is created (the very first browser, the first spreadsheet, the first music downloader,... ), nobody knows much about it. So the creator adds feature after feature. By the time 3.0 or 4.0 comes out, people pretty much know what the application is all about. 'Killer apps' will have millions of users by then. At this point, all of those users have a hard-wired notion of what that kind of application does. For a browser, for example, it views web pages, has a back and forward button and you can use bookmarks. Any feature you add beyond the 3.0/4.0 release simply gets ignored. The users don't care any more about features.

Microsoft keeps coming out with new versions of Office. Every version has lots of features, but no one notices them. Some people yell 'Bloat!", and complain. People figured out what a word processor was supposed to do 10 years ago. Features added after people decided on what the hard-wired definition of word processor was simply go unnoticed, regardless of how useful they might be.

People won't switch to Mozilla or Firebird because of any great features, because those features aren't what people think of as a browser. The only way to get people to use a browser is if that browser is something else. Like, a complex information-overflown workflow organizer.

Oh, and to anyone who wants to create that, don't put a Back button in it -- people will think it's a browser.