It's the day after a launch and your client calls you in a sheer panic. Traffic is not as high as they'd like! Why aren't their new social media features paying off? Don't you know what you're doing? And to top it all off the site is slow! You need to fix this now.
As you listen to your client yell, you drift back in time to that first meeting where you both are posturing and laying down the ground rules for each other. Business as usual planning out the new details with excitement and anticipation.
And then the moment comes back to you. The moment when you said nonchalantly, "We can do that feature, but it may cause the site to slow down. Why is this feature so important?" And the client, also nonchalantly said, "We just need it, our competitors all have it." And you both went back to going over the other features on the list, not realizing that you had just wasted thousands of your client's dollars and hours of your life on something that most users don't give a flying flip about bringing almost zero value to the world, all because everybody's doing it. This is how the business just works, and hardly anyone ever questions it.