One of the sessions I enjoyed at SXSW this year was Jason Fried's talk on Stuff We've Learned at 37signals. As expected, Jason stressed simplicity, efficiency, and sustainability (in the form of fee-based software). He talked about not planning too far ahead, and being flexible as your business evolves. It reminded me of a challenge a lot of entrepreneurs seem to have: maintaining a rigid focus on a clear vision for their business while at the same time being nimble enough to react to the market and course-correct as needed. At Viget, we apply Agile methods, so we release software early and often, allowing user feedback and actual usage data to influence subsequent releases. Even if that meant that we could make drastic changes to a web product every time we got an astute user comment or when feature adoption ramped more slowly than expected, it doesn't mean we should make such changes. 37signals' thing is "simple, affordable software." That's cool (and, as it turns out, lucrative). So, when someone asks for a feature that seems logical but threatens their "thing," they don't do it. When you're starting a company, be nimble. Let the constantly evolving market and competition influence your day-to-day decisions and hone your company to be the best it can be. But do so with a clear, unwavering vision for what the core of your business really is. Without that, you'll just tweak yourself into eventual failure.