Getting Real by 37 Signals is a specific read, for a specific audience, but it does a tremendous job outlining a different approach to web application development. Their approach revolves around getting something real and usable out. That point is made repeatedly, inline with the style of Seth Godin. Reiterate the same point until it's engrained in your consciousness.
The initial mission of Getting Real is to aid anyone involved with the development/deployment of a web application. It begins to do so by having you, the owner of the application, define it's purpose, audience, and go through all the different life cycles of the application. These include the design, hiring, marketing, pricing, and feedback processes.
What comes through most in Getting Real is the optimism of a minimalist approach to web development and design. This stretches from the initial feature sets, through to the number of people required to launch it. Less is more in the eyes of Getting Real, and they do an exceptional job explaining why this is.
Being a user of Highrise, a lean CRM web service, it is clear from the onset that 37 Signals believes firmly and practices strictly the process of less is more. Highrise, for example, has a very limited feature set compared to other CRM systems, however the fact that it is so lean is what makes it so easy to get involved with. The learning curve is shallow, and it's flexibility in a few areas (eg. tagging) make it as powerful as the user/business needs.
My contribution to this discussion is something that's taken me a very long time to understand: if you are developing something that has competition (which most do), figure out the reason you want to compete, that one specific reason, and do nothing else.
A few years ago I created a web application that allowed a visitor to post a vacation property they owned, and I would manage the SEO/SEM on their behalf. They would pay a yearly subscription fee, in exchange for the site facilitating the submission of inquiries by potential vacation property renters. Baldly, a directory service.
There were many out there, and while often a reason for creating a product or service will be to make money, initially mine was to improve the design and experience of those sites. vrbo.com is one such competitor, and while the design of their site has improved, for a long time I found it tremendeously difficult to use. It was functional, but not optimized for a web experience.
But rather than spend 95% of my time on addressing the experience challenges I found with my competitors, I tried to mimic all the functionality vrbo.com in addition to improving the experience.
Like many businesses, it failed. I made some money, but little compared to the size of the market, and in no way sustainable. However over the past few years, it's become clear to me that when trying to compete in a specific vertical, 95% of my time should be focused on a core competancy.
Getting Real is a great read for anyone who develops sites/applications, or has a desire to be involved in that industry. It will fairly radically change the way you look at feature sets, deadlines, team oriented development, and more than anything, priorities for your sites/applications.