Below is one of the most insightful things I've heard anyone say about web development. Truthfully, the same is true about business design these days. If you aren't constantly evolving in response to changes by your competitor, your customers will be drawn away. 

Coconut Headsets: Dynamic Web Strategy and The Failure Of Best Practices, 2012-Mar-19, by Rob May

One of the difficult things about redesigning a company website is that everyone has an opinion. What’s worse is that everyone has data to back it up.