Though it's not said, I get the impression that they were technical co-workers... so I need to point out you need "technical skills for technical success; business skills for business success".<p>I've seen developers work hard on cool features that no one needs, or are too hard to use, or meet a need better met elsewhere. These mistakes are due to not seeing from the user's perspective - and yes, I'd classify doing so as a business skill.<p>They won't communicate why it's worth using, see how it fits in with what people want to do, allow it to be difficult to try out (download, install, get started, learn). An easy way to address all these is ensure you yourself are a user (and representive of a sufficiently large segment of users).<p>I believe that if you really know what you're doing, you don't need to work very hard, placing focussed leverage on just the right point to make everything happen (caveats: 1. if you want <i>enormous</i> success, there'll be competition and you'll have to work hard; 2. the big problem is that we <i>don't</i> know what we're doing - in a sense, finding out the actual work of a start-up).